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商品脂肪酶降解壳聚糖机理研究
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摘要
商品脂肪酶具有非专一性降解壳聚糖的活力,但对于脂肪酶降解壳聚糖的机理在国内外均未见报道。本论文研究商品脂肪酶对壳聚糖的降解特性以及作用机理,这对于阐明非专一性酶水解壳聚糖机理具有重要的理论价值和学术意义,同时对于指导低分子量壳聚糖(LMWC)和甲壳低聚糖(COS)的工业化酶法生产也具有重要的现实意义。
     首先从四种不同来源的商品脂肪酶中选择了一种来源于Aspergillus Oryzae的具有较强壳聚糖水解活力的脂肪酶,研究了该酶降解壳聚糖的特性,并对该酶降解壳聚糖的产物进行了分析。脂肪酶对不同脱乙酰度(DD)的壳聚糖均有显著的水解作用,作用于DD为64%、73%、82%和90%的壳聚糖的最适pH值分别为4.2、4.4、4.6和5.0,最适温度均为60℃。脂肪酶水解不同DD壳聚糖的反应均遵循Michaelis-Meten方程,动力学分析结果表明DD值为73%和82%的壳聚糖是脂肪酶较容易水解的底物。脂肪酶催化壳聚糖降解可生成各种聚合度(DP = 2~6)的低聚糖,但在反应的最后,产物仅剩下氨基葡萄糖(GlcN),这表明在脂肪酶中存在外切酶。脂肪酶催化不同DD壳聚糖水解生成的产物完全相同。
     采用超滤、DEAE-Sepharose CL-6B离子交换层析、Phenyl Sepharose CL-4B疏水作用层析和Sephacryl S-200凝胶过滤层析等一系列分离纯化操作,从脂肪酶中分离得到一个具有壳聚糖酶活力但不具有脂肪酶活力的酶组分。HPLC结果表明纯化酶的纯度达到99%以上,SDS-PAGE结果表明纯化酶已经达到均一。由于分离纯化过程中其他组分均不具备壳聚糖酶活力,因此说明脂肪酶的壳聚糖酶活力是由纯化酶的水解作用引起的。SDS-PAGE测得纯化酶的分子量约为74 kDa,而在非还原SDS-PAGE条件下纯化酶条带出现在130 kDa附近,表明纯化酶由两个相对分子质量相同的亚基组成,而且这两个亚基通过二硫键连接在一起。
     利用氨基酸自动分析仪测定了纯化酶的氨基酸组成,结果表明天冬氨酸和谷氨酸含量较高,组氨酸、精氨酸和赖氨酸等碱性氨基酸的含量较低;含硫氨基酸的含量都非常低,而丝氨酸、甘氨酸、苏氨酸和丙氨酸等中性氨基酸的含量都较高。采用Edman降解法测得纯化酶N-末端12个氨基酸的序列为Ala– Leu– Arg– Leu– Asn– Ser– Pro– Asn– Asn– Ile– Ala– Val。在非冗余蛋白质序列( Non-redundant protein sequences)数据库中采用NCBI Blastp2程序对测得的N-末端氨基酸序列进行相似性比较,发现该酶与来自米曲霉的一个蛋白质具有很高的相似性,12个氨基酸序列的区域一致性达到100%。
     采用DEPC、NBS、Ch-T、EDAC、PMSF、CHD、NAI、DTNB和DTT等化学修饰剂对纯化酶的氨基酸残基进行修饰,研究了纯化酶中必需基团的组成。DEPC对酶的修饰结果表明有1分子组氨酸残基位于纯化酶的活性中心;利用NBS修饰酶蛋白,结果表明色氨酸残基处于酶的活性中心,且至少有1分子色氨酸残基位于酶活性中心的底物结合部位;Ch-T和EDAC对酶的修饰结果表明甲硫氨酸残基和羧基也是酶的必需基团。利用PMSF、CHD、NAI、DTNB和DTT分别对酶分子中的羟基、精氨酸残基、酪氨酸残基、巯基和二硫键进行修饰,结果表明这些修饰剂在较高的浓度范围内均没有引起酶活的显著降低,因此羟基、精氨酸残基、酪氨酸残基、巯基和二硫键都不是维持酶活的必需基团。
     研究了纯化酶的酶学性质,结果表明纯化酶在pH 4.6时的活力较高,在pH4.5 ~ 9.5之间具有较好的稳定性;在60℃时活力达到最高,在低于60℃的温度下时具有较高的热稳定性。Ni2+、Co2+和Mn2+等金属离子对酶的活力具有明显的激活作用,而Fe3+、Sn2+、Pb2+和Hg2+则能强烈抑制酶活,其中Hg2+的抑制能力最强,Na+、K+、Mg2+、Zn2+和Cd2+对酶活的影响较小。纯化酶对于DD为73%、81%和82%的壳聚糖显示了较高的水解活力,而对DD为64%和90%的壳聚糖的水解活力较低。
     通过TLC法和HPLC法分析纯化酶降解已知结构甲壳低聚糖和乙酰甲壳低聚糖的产物,研究了纯化酶的作用模式。结果表明纯化酶以外切的形式作用于甲壳低聚糖,并将单糖GlcN顺次从甲壳低聚糖的末端释放出来,这与氨基葡萄糖苷酶(GlcNase)的作用模式是一致的;同时纯化酶以外切酶的形式作用于乙酰甲壳低聚糖的末端,并依次将乙酰甲壳二糖[(GlcNAc)2]释放出来,这是乙酰甲壳二糖苷酶典型的作用模式。因此该酶同时具有GlcNase活力和乙酰甲壳二糖苷酶活力,既能水解壳聚糖中GlcN-GlcN之间的糖苷键,也能水解GlcNAc-GlcNAc之间的糖苷键。
     本论文通过超滤、凝胶过滤层析、疏水作用层析和离子交换层析等分离纯化技术,从脂肪酶中得到了一种具有壳聚糖水解活力但不具有脂肪酶活力的酶组分,该酶具有GlcNase和乙酰甲壳二糖苷酶双重活力,说明该酶的水解作用是脂肪酶降解壳聚糖的主要原因,从而阐明了商品脂肪酶非专一性降解壳聚糖的机理。
Commercial lipases exhibit non-specific activity on chitosan depolymerization, however, no research on mechanicsm of chitosan deploymerization by lipase has been reported at home and abroad. In this study, characteristics and mechanism of chitosan hydrolysis by a commercial lipase were investigated, which is of important theoretical and academic value in elucidating mechanism of chitosan hydrolysis by non-specific enzymes and of practical significance in instructing industrial enzymatic production of low molecular chitosan and chitooligosaccharides (COS).
     Characteristics of chitosan hydrolysis by a commercial lipase from Aspergillus oryzae were investigated and hydrolysis products were analyzed. The lipase showed obvious hydrolytic activity on chitosans with different degrees of deacetylation (DD). The optimum pH values of the lipase on chitosans with DD of 64%, 73%, 82%, and 90% were 4.2, 4.4, 4.6, and 5.0, respectively, and optimum temperatures were all 60℃. The hydrolysis reactions of the lipase on different chitosans obeyed Michaelis-Meten equation, and kinetic parameters indicate that chitosans with DD of 73% and 82% were susceptible to be hydrolyzed. Products of chitosan hydrolysis by lipase included chitosan-oligomers with degree of polymerization (DP) 2~6, but the final product was glucosamine (GlcN), indicating some hydrolase with exo-mode action existing in the lipase. Products of hydrolysis of chitosans with different DD catalyzed by the lipase were identical.
     A hydrolase with chitosanolytic activity but no lipolytic activity was purified from lipase by using a combination of ultrafiltration, DEAE-Sepharose CL-6B ion exchange chromatography, Phenyl-Sepharose CL-4B hydrophobic interaction chromatography, and Sephacryl S-200 gel filtration chromatography. Results of HPLC and SDS-PAGE show that the hydrolase had been purified to homogeneity. Because no other components of the lipase showed chitosanolytic activity during purification process, chitosanolytic activity the lipase exhibited was caused by the purified enzyme. Molecular mass of the purified enzyme estimated by SDS-PAGE and non-reducing SDS-PAGE was about 74 kDa and 130 kDa, respectively, indicating that the enzyme was composed of two identical subunits bound together with disulfide bonds.
     Amino acids composition of the purified enzyme was analyzed by auto-amino acids analyzer. The results show that concentrations of Asp and Glu were high, those of His, Arg, and Lys were low, while those of sulfur-containing amino acids were extremely low. The N-terminal sequence containing 12 amino acids of the purified enzyme determined by using the Edman degradation technique was Ala– Leu– Arg– Leu– Asn– Ser– Pro– Asn– Asn– Ile– Ala– Val. The similarity of the N-terminal sequence was blasted in the Non-redundant Protein Sequences database using the NCBI Blastp2 program, and it was found that this sequence was similar to that of a protein from Aspergillus oryzae, and the identity of the 12 amino acids was 100%.
     The purified enzyme was modified by DEPC, NBS, Ch-T, EDAC, PMSF, CHD, NAI, DTNB, and DTT. Modification of the purified enzyme by DEPC shows that 1 mole of histidine residue existed in the active site of the enzyme. Modification by NBS shows that tryptophan residues existed in the active site and there is at least 1 mole of tryptophan residue in the substrate binding site. Results of modification by Ch-T and EDAC indicate that methionine residues and carbosyl groups were essential groups of the purified enzyme. In addition, hydroxyl groups, arginine residues, tyrosine residues, sulfhydryl groups, and disulfide bonds were not essential groups of the purified enzyme.
     The enzyme showed the optimum action pH value and temperature were 4.6 and 60?C, respectively, and it was stable in pH range of 4.5~9.5 and at temperatures lower than 60?C. Metal ions such as Ni2+, Co2+, and Mn2+ had obvious activation effects on the enzymatic activity, while Fe3+, Sn2+, Pb2+, and Hg2+ inactivated the enzyme, and Na+, K+, Mg2+, Zn2+, and Cd2+ had no obvious effect on the purified enzyme. The enzyme exhibited higher chitosanolytic activity toward chitosans which were 73%, 81% and 82% deacetylated and lower activity to chitosans with DD of 64% and 90%.
     The action mode of the purified enzyme was studied. TLC method and HPLC method were used to analyze the hydrolysis products of standard compounds (chitosan-oligomers and chitin-oligomers) catalyzed by the purified enzyme. The results show that the purified enzyme acted in an exo-mode and released GlcN residues successively from chitosan-oligomers, which is the characteristic of exo-β-D-glucosaminidase (GlcNase). In addition, the enzyme acted in an exo-mode on and released (GlcNAc)2 successively from chitin– oligomers, which is the characteristic of chitobiosidase. Therefore, the purified enzyme exhibited both GlcNase activity and chitobiosidase activity, and split glycoside bonds between GlcN-GlcN and GlcNAc-GlcNAc.
     In this study, a hydrolase with chitosanolytic activity but no lipolytic activity was purified from a commercial lipase to homogeneity by using a combination of ion exchange chromatography, hydrophobic interaction chromatography, and gel filtration chromatography. The purified enzyme exhibited both GlcNase activity and chitobiosidase activity, therefore, the chitosanolytic activity the lipase exhibited was caused by the purified enzyme.
引文
1. Kurita K. Chitin and chitosan: functional biopolymers from marine crustaceans [J]. Mar Biotechnol, 2006, 1:1-24
    2. Kim S K, Rajapakse N. Enzymatic production and biological activities of chitosan oligosaccharides (COS): A review [J].Carbohyd Polym, 2005, 62: 357-368
    3.魏新林,夏文水.甲壳低聚糖的生理活性研究进展[J].中国药理学通报,2003,(6):614-617
    4. Jeon Y J, Shahidi F, Kim S K. Preparation of chitin and chitosan oligomers and their applications in physiological functional foods [J]. Food Rev Int, 2000, 16(2): 159-176
    5. Pantaleone D, Yalpani M, Schollar M. Unusual susceptibility of chitosan to enzymic hydrolysis [J]. Carbohyd Res, 1992, 237:325-332
    6. Yalpani M, Pantaleone D. An examination of the unusual susceptibilities of aminoglycans to enzymatic hydrolysis [J]. Carbohyd Res, 1994, 256: 159-175
    7. Qin C, Zhou B, Zeng L, etc. The physicochemical properties and antitumor activity of cellulose-treated chitosan [J]. Food Chem, 2004, 84: 107-115
    8. Zhang H, Du Y, Yu X, etc. Preparation of chitooligosaccharides from chitosan by a complex enzyme [J]. Carbohyd Res, 1999, 320: 257-260
    9 . Muraki E, Yaku F, Kojima H. Preparation and crystallization of D-glucosamine oligosaccharides with dp 6-8 [J]. Carbohyd Res, 1993, 239: 227-237
    10. Qin C, Du Y, Zong L, etc. Effect of hemicellulase on the molecular weight and structure of chitosan [J]. Polym Degrad Stabil, 2003, 80: 435–441
    11. Shin-ya Y, Lee M Y, Hinode H, etc. Effects of N-acetylation degree on N-acetylated chitosan hydrolysis with commercially available and modified pectinases [J]. Biochem Eng J, 2001, 7: 85–88
    12. Zhang, H, Neau S H. In vitro degradation of chitosan by a commercial enzyme preparation: effect of molecular weight and degree of deacetylation [J]. Biomaterials,2001, 22:1653-1658
    13. Kumar A V, Varadaraj M C, Lalitha R G, etc. Low molecular weight chitosans: preparation with the aid of papain and characterization [J]. BBA, 2004, 1670: 137-146
    14 . Terbojevich M, Cosani A, Muzzarelli R. Molecular parameters of chitosans depolymerized with the aid of papain [J]. Carbohyd Polym, 1995, 29(1): 63-68
    15. Kumar A V, Tharanathan R N. A comparative study on depolymerization of chitosan by proteolytic enzymes [J]. Carbohyd Polym, 2004, 58: 275–283
    16. Roncal T, Oviedo A, Armentia I L, etc. High yield production of monomer-free chitosan oligosaccharides by pepsin catalyzed hydrolysis of a high deacetylation degree chitosan. Carbohyd Res, 2007, 342: 2750–2756
    17.周桂,谭学才,黄在银,等.胰蛋白酶对壳聚糖的降解研究.广西农业生物科学, 2002, 21(1): 50-53
    18. Kumar A V, Gowda L R, Tharanathan R N. Non-specific depolymerization of chitosan bypronase and characterization of the resultant products [J]. Eur J Biochem, 2004, 271: 713-723
    19. Muzzarelli R, Xia W, Tomasetti M, etc. Depolymerization of chitosan and substituted chitosans with the aid of a wheat germ lipase preparation [J]. Enzyme Microb Tech, 1995, 17:541-545
    20. Shin S S, Lee Y C, Lee C. The degradation of chitosan with the aid of lipase from Rhizopus japonicus for the production of soluble chitosan [J]. J Food Biochem, 2001, 25: 307-321
    21. Woolley P, Petersen SB. Lipases: their structure, biochemistry, and application [M]. Cambridge: Cambridge University Press, 1994
    22.马如,黄明智.脂肪酶降解壳聚糖的反应动力学研究[J].化学世界,2002, 43(9):472-475.
    23.周孙英,余萍,陈盛,等.脂肪酶催化壳聚糖降解的特性[J].福建医科大学学报, 2002, 36(3): 302-305
    24.王丽娟,夏文水,陈小娥,等.脂肪酶水解壳聚糖作用研究[J].食品工业科技,2004,25(5): 51-53
    25. Balashev K, Jensen T R, Kjaer K, etc. Novel methods for studying lipids and lipases and their mutual interaction at interfaces: Part I. Atomic force microscopy [J]. Biochimie, 2001,83:387–97
    26. Jaeger K E, Ransac S, Dijkstra B W, etc. Bacterial lipases [J]. FEMS Microbiol Reviews, 1994, 15: 29-63
    27. Sharma R, Chisti Y, Banerjee U C. Production, purification, characterization, and applications of lipases [J]. Biotechnol Advances, 2001, 19: 627-662
    28. Vulfson E N. Industrial applications of lipases [C]. In: Woolley P, Peterson S B, eds. Lipases - their structure, biochemistry and applications. Cambridge: Cambridge Univ. Press, 1994. 271–288
    29.方兆华.脂肪酶与手性苯氧丙酸类除草剂的对映选择性相互作用[D]:[博士学位论文].杭州:浙江大学,2005
    30 . Muralidhar R V, Chirumamilla R R, Marchant R, etc. Understanding lipase stereoselectivity [J]. World J Microbiol Biotechnol, 2002, 18:81–97
    31. Drozozowski A M, Derewenda U, Derewenda Z S, etc. A model for interfacial activation in lipases from the structure of a fungal lipase–inhibitor complex [J]. Nature, 1991, 351: 491-494
    32. Wang Y, Srivastava K C, Shen G J, etc. Thermostable alkaline lipase from a newly isolated thermophilic Bacillus, strain A30-1 (ATCC 53841) [J]. J Ferment Bioeng, 1995, 79:433–438
    33. Misset O, Gerritse G, Jaeger K E, etc. The structure function relationship of the lipases from Pseudomonas aeruginosa and Bacillus subtilis [J]. Protein Eng, 1994, 7:523–529
    34. Dharmsthiti S, Luchai S. Production, purification and characterization of thermophilic lipase from Bacillus sp.THL027 [J]. FEMS Microbiol Lett, 1999, 179:241–246
    35. Kordel M, Hofmann B, Schaumburg D, etc. Extracellular lipase of Pseudomonas sp. strain ATCC 21808: purification, characterization, crystallization and preliminary Xray diffraction data [J]. J Bacteriol, 1991,173:4836–4841
    36. Angultra J, Rodrigue Z, Aparicio L B, etc. Purification, gene cloning, amino acid sequence analysis and expression of an extracellular lipase from an Aeromonas hydrophila human isolate [J]. Appl Environ Microbiol,1993, 59:2411–2417
    37. Lotti M, Alberghina L. Lipases: molecular structure and function [C]. In: Polaina J, MacCabe A P, eds. Industrial Enzymes: Structure, Function and Applications. Berlin: Springer Verlag, 2007. 263-281
    38.曹淑桂.脂肪酶的底物特异性及其应用潜力[J].生物化学与生物物理进展, 1995, 22(1):9-13
    39. Weete J D. Microbial Lipases [C]. In: Akoh C C, Min D B, eds. Food lipids: Chemistry, Nutrition, and Biotechnology. New York: Marcel Dekker, 1998. 813-838
    40. Ota Y, Sawamoto T, Hasuo M. Tributyrin specifically induces a lipase with a preference for the Sn-2 position of triglyceride in Geotrichum sp. FO401B [J]. Biosci Biotech Bioch, 2000, 64(11): 2497-2477
    41. Sugihara A, Shimada Y, Nakamura M, etc. Positional and fatty acid specificities of Geotrichum candidum lipases [J]. Protein Engineering, 1994, 7(4): 585-588
    42. Reetz M T, Jaeger K E. Overexpression, immobilization and biotechnological application of Pseudomonas lipases [J]. Chem Phys Lipids, 1998, 93:3-14
    43.聂尧,徐岩,王栋.脂肪酶不对称立体选择性能改善的研究进展[J].过程工程学报, 2002, 2(6): 570-576
    44. Fisher M, Pleiss J. The lipase engineering database: a navigation and analysis tool for protein families [J]. Nucl Acid Res, 2003, 31(1):319-321
    45. Ollis D L, Cheah E, Cygler M, etc. The alpha/beta hydrolase fold [J]. Prot Eng, 1992, 5: 197-211
    46. Sarda L, Desnuelle P. Action de la lipase pancreatique sur les esters en emulsion [J]. Biochim Biophys Acta, 1958, 30: 513-521
    47. Brady L, Brzozowski A M, Derewenda Z S, etc. A serine protease triad forms the catalytic center of a triacylglycerol lipase [J]. Nature, 1990, 343, 767–770
    48. Winkler F K, D’Arcy A, Hunziker W. Structure of human pancreatic lipase [J]. Nature, 1990, 343: 771-774
    49. Grochulski P, Li Y, Schrag J D, etc. Two conformational states of Candida rugosa lipase [J]. Prot Sci, 1994, 3: 82-91
    50. Cernia E, Palocci C. Lipases in supercritical fluids [J]. Methods Enzymol, 1997, 286: 495-508
    51. Villeneuve P, Muderhwa J M, Graille J, etc. Customizing lipases for biocatalysis: a survey of chemical, physical and molecular biological approaches [J]. J Mol Catal B: Enzymatic, 2000, 9: 113-148
    52. Park S, Kazlauskas R J. Biocatalysis in ionic liquids-advantages beyond green technology [J]. Curr Opin Biotechnol, 2003, 14:432-437
    53. Pleiss J, Fisher M, Schmid R D. Anatomy of lipase binding sites: the scissile fatty acid binding sites [J]. Chem Phys Lipids, 1998,93:67-80
    54. Schmitt J, Brocca S, Schmid R D, etc. Blocking the tunnel: engineering of Candida rugosa lipase mutants with short chain length specificity [J]. Protein Engineering, 2002, 15: 595-601
    55. Ransac S, Rogalska E, Gargouri Y, etc. Stereoselectivity of lipases. I. Hydrolysis of enantiomeric glyceride analogues by gastric and pancreatic lipases, a kinetic study using the monomolecular film technique [J]. Journal of Biological Chemistry, 1990, 265(33):20263-20270
    56. Kovac A, Scheib H, Pleiss J, etc. Molecular basis of lipase stereoselectivity [J]. Eur J Lipid Sci Technol, 2000, 102: 61-77
    57. Carriere F, Withers-Martinez C, van Tilbeurgh H, etc. Structural basis for the substrate selectivity of pancreatic lipases and some related proteins [J]. Biochimica et Biophysica Acta, 1998,1376:417-432
    58. Eggert T, Leggewie C, Puls M, etc. Novel Biocatalysts by identification and design [J]. Biocat Biotrans, 2004,22:139-144
    59. Davis B, Eveleigh D E. Chitosanase: occurrence, production and immobilization [C]. In: Zikakis J P, Eds. Chitin, chitosan, and related enzymes. New York: Academic Press, FL, 1984. 161-179
    60. Tanaka T, Fukui T, Fujiwara S, etc. Concerted action of diacetylchitobiose deacetylase and exo-β-D-glucosaminidase in a novel chitinolytic pathway in the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1[J]. Jouranl of Biochemistry, 2004, 279(29): 30021-30027
    61. Nanjo F, Katsumi R, Sakai K. Purification and characterization of an exo–β– D - glucosaminidase, a novel type of enzyme, from Nocardia orientalis [J]. J Biol Chem, 1990, 265: 10088-10094
    62 Nogawa M, Takahashi H, Kashiwagi A, etc. Purification and characterization of exo-β-D-glucosaminidase from a cellulolytic fungus, Trichoderma reesei PC-3-7 [J]. Appl Environ Microb, 1998,64: 890-895
    63. Davis B, Eveleigh D E. Chitosanase: occurrence, production and immobilization [C]. In: Zikakis J P, Eds. Chitin, chitosan, and related enzymes. New York: Academic Press, FL,1984. 161-179
    64. Adachi W, Sakihama Y, Shimizu S, etc. Crystal structure of family GH-8 chitosanase with subclass II specificity from Bacillus sp. K17 [J]. Journal of Molecular Biology, 2004, 343: 785-795
    65 . Fukamizo T, Brzezinski R. Chitosanase from Streptomyces sp. Strain N174: a comparative review of its structure and function [J]. Biochem Cell Biol, 1997, 75: 687-696
    66. Chen X, Xia W, Yu X. Purification and characterization of two types of chitosanase from Aspergillus sp. CJ22-326 [J]. Food Res Int, 2005,38: 315-322
    67. Osswald W F, Shapiro J P, Doostdar H, etc. Identification and characterization of acidic hydrolases with chitinase and chitosanase activities from sweet orange callus tissue [J]. Plant Cell Physiol, 1994, 35:811-820
    68. Henrissat B. A classification of glycosyl hydrolases based on amino-acid sequence similarities [J]. Biochem J, 1991,280: 309-316
    69 . Henrissat B, Bairoch A. Updating the sequence-based classification of glycosyl hydrolases [J]. Biochem J,1996,316: 695-696
    70. Ike M, Ko Y, Yokoyama K, etc. Cellobiohydrolase I (Cel7A) from Trichoderma reesei has chitosanase activity [J]. Journal of Molecular Catalysis B: Enzymatic, 2007, 47: 159-163
    71. Somashekar D, Joseph R. Chitosanase– Properties and applications: a review [J]. Bioresource Technology, 1996, 55: 35-45
    72 . Jung W J, Kuk J H, Kim KY, etc. Purification and characterization of exo-β-D-glucosaminidase from Aspergillus fumigatus S-26 [J]. Protein Expres Purif, 2006, 45: 125-131
    73. Shimosaka M, Nagawa M, Ohno Y, etc. Chitosanase from the plant pathogenic fungus, Fusarium solani F. sp. Phaseoli purification and some propertyes [J]. Biosci Biotechnol Biochem, 1993, 57: 231-235
    74. Boucher I, Dupuy A, Vidal P, etc. Purification and characterization of a chitosanase from Streptomyces N174 [J]. Appl Microbiol Biotechnol, 1992, 38: 188-193
    75. Sakai K, Katsumi R, Isobe A, etc. Purification and hydrolytic action of a chitosanase from Nocardia orientalis [J]. Biochem Biophys Acta, 1991, 1097: 65-72
    76 . Fukamizo T, Brzezinski R. Chitosanase from Streptomyces sp. Strain N174: a comparative review of its structure and function [J]. Biochemistry and Cell Biology, 1997, 75: 687-696
    77. Price J S, Storck R. Production, purification and characterization of an extracellular chitosanase from Streptomyces [J]. J Bact, 1975, 124: 1574-1585
    78.方文建,隋斯光,郑连英.青霉菌产壳聚糖酶制备低分子量壳聚糖的研究[J].中国医药工业杂志, 2006, 37(2): 85-88
    79. Hsiao Y C, Lin Y W, Su C K, etc. High degree polymerized chitooligosaccharides synthesis by chitosanase in the bulk aqueous system and reversed micellar microreactors Process [J]. Biochemistry, 2008, 43: 76–82
    80.陈石根,周润琦.酶学[M].上海:复旦大学出版社, 2001. 156-162
    81. Kuroiwa T, Noguchi Y, Nakajima M, etc. Production of chitosan oligosaccharides using chitosanase immobilized on amylose-coated magnetic nanoparticles [J]. Process Biochem, 2008, 43: 62-69
    82. Zeng J, Zheng L Y. Studies on Penicillium sp. ZDZ1 chitosanase immobilized on chitin by cross-linking reaction [J]. Process Biochem, 2002, 38: 531-535
    83. Zeng J, Zheng L Y. Studies on Penicillium sp. ZDZ1 chitosanase immobilized on chitin by cross-linking reaction [J]. Process Biochem, 2002, 38: 531-535
    84. Ming M, Kuroiwa T, Ichikawa S, etc. Production of chitosan oligosaccharides by chitosanase immobilized on an agar gel-coated multidisk [J]. Biochemical Engineering Journal, 2006, 28: 289–294
    85.李亚玲,嗜热真菌热稳定纤维素酶的分离纯化及基因的克隆与表达[D]:[博士学位论文].济南:山东农业大学植物保护学院, 2007
    86.刘靖,夏文水.纤维素酶水解壳聚糖的特性研究[J].食品工业科技,2005,26(12): 157-160
    87.刘同军,张玉臻.半纤维素酶的应用进展[J].食品与发酵工业, 1998, 24(6): 58-61
    88. Kittur F S, Kumar A, Gowda L R, etc. Chitosanolysis by a pectinase isozyme of Aspergillus niger—a non-specific activity [J]. Carbohydrate Polymers, 2003, 53: 191–196
    89. Kittur F S, Kumar A, Tharanathan R N, etc. Low molecular weight chitosans - preparation by depolymerization with Aspergillus niger pectinase, and characterization [J]. Carbohyd Res, 2003, 338 :1283-1290
    90. Kittur F S, Kumar A, Varadaraj M C. etc. Chitooligosaccharides - preparation with the aid of pectinase isozyme from Aspergillus niger and their antibacterial activity [J]. Carbohyd Res, 2005, 340:1239-1245
    91. Terbojevich M, Cosani A, Muzzarelli R A A. Molecular parameters of chitosans depolymerized with the aid of papain [J]. Carbohyd Polym, 1996, 29(1): 63-68
    92.苏畅,夏文水,姚惠源.木瓜蛋白酶降解壳聚糖[J].无锡轻工大学学报, 2002, 21(2): 112-115
    93. Kumar A, Varadaraj M C, Gowda L R, etc. Characterization of chitooligosaccharides prepared by chitosanolysis with the aid of papain and pronase, and their bactericidal action against Bacillus cereus and Escherichia coli [J]. Biochemical Journal, 2005, 391:167-175
    94.刘靖.纤维素酶水解壳聚糖的特性及机理研究[D]:[博士学位论文].无锡:江南大学,2006
    95. Xia W S, Liu P, Liu J. Advance in chitosan hydrolysis by non-specific cellulases, Bioresource Technology, 2008, 99: 6751-6762
    96. Hung T H, Fu J Y, Chiang C L, etc. Purification and characterization of hydrolase with chitinase and chitosanase activity from commercial stem bromelain [J]. Journal of Agricultural and Food Chemistry, 2002, 50: 4666-4673
    97. Fu J Y, Wu S M, Chang C T, etc. Characterization of three chitosanase isozymes isolated from a commercial crude porcine pepsin preparation [J]. Journal of Agricultural and Food Chemistry, 2003, 51: 1042-1048
    98. Chiang C L, Chang Y M, Chang C T, etc. Characterization of a chitosanase isolated from a commercial ficin preparation [J]. Journal of Agricultural and Food Chemistry, 2005, 53: 7579-7585
    1 . Muralidhar R V, Chirumamilla R R, Marchant R, etc. Understanding lipase stereoselectivity [J]. World J Microbiol Biotechnol, 2002, 18: 81–97
    2. Pantaleone D, Yalpani M, Schollar M. Unusual susceptibility of chitosan to enzymic hydrolysis [J]. Carbohydrate Research, 1992, 237:325-332
    3. Yalpani M, Pantaleone D. An examination of the unusual susceptibilities of aminoglycans to enzymatic hydrolysis [J]. Carbohydrate Research, 1994, 256: 159-175
    4. Zhang H, Du Y, Yu X, etc. Preparation of chitooligosaccharides from chitosan by a complex enzyme [J]. Carbohyd Res, 1999, 320: 257-260
    5 . Muraki E, Yaku F, Kojima H. Preparation and crystallization of D-glucosamine oligosaccharides with dp 6-8 [J]. Carbohyd Res, 1993, 239: 227-237
    6. Shin-ya Y, Lee M Y, Hinode H, etc. Effects of N-acetylation degree on N-acetylated chitosan hydrolysis with commercially available and modified pectinases [J]. Biochem Eng J, 2001, 7: 85–88
    7. Kittur F S, Kumar A, Tharanathan R N, etc. Low molecular weight chitosans - preparation by depolymerization with Aspergillus niger pectinase, and characterization [J]. Carbohyd Res, 2003, 338 :1283-1290
    8. Kumar A V, Varadaraj M C, Lalitha R G, etc. Low molecular weight chitosans: preparation with the aid of papain and characterization [J]. BBA, 2004, 1670: 137-146
    9. Roncal T, Oviedo A, Armentia I L, etc. High yield production of monomer-free chitosan oligosaccharides by pepsin catalyzed hydrolysis of a high deacetylation degree chitosan. Carbohyd Res, 2007, 342: 2750–2756
    10. Muzzarelli R A A, Xia W, Tomasetti, etc. Depolymerization of chitosan substituted chitosans with the aid of a wheat germ lipase preparation [J]. Enzyme and Microbial Technology, 1995, 17: 541-541
    11. Shin S S, Lee Y C, Lee C. The degradation of chitosan with the aid of lipase from Rhizopus japonicus for the production of soluble chitosan [J]. J Food Biochem, 2001,25:307-321
    12.蒋挺大.壳聚糖[M].北京:化学工业出版社,2001.259-263
    13. Wang W, Bo S, Qin W. Determination of the Mark– Houwink equation for chitosans with different degrees of deacetylation [J]. Int J Biol Macromol, 1991, 13(10):281-285
    14. Lineweaver H, Burk D. The determination of enzyme dissociation constants. J Am Chem Soc, 1934, 56: 658-666
    15.刘靖.纤维素酶水解壳聚糖的特性及机理研究[D]:[博士学位论文].无锡:江南大学, 2006
    16. Imoto T, Yagishita K. A simple activity measurement of lysozyme [J]. Agricultural and Biological Chemistry, 1971,35: 1154-1156
    17.蒋挺大.壳聚糖[M].北京:化学工业出版社,2001.12-13
    18.王镜岩,朱对庚,徐长法.生物化学(第三版)[M].北京:高等教育出版社,2002. 359-360
    19.蒋挺大.甲壳素[M].北京:化学工业出版社, 2003. 33-41
    20. Kumar A V, Varadaraj M C, Lalitha R G, etc. Low molecular weight chitosans: preparation with the aid of papain and characterization [J]. Biochimica et Biophysica Acta, 2004, 1670: 137-146
    21.张惟杰.糖复合物生化研究技术[M].杭州:浙江大学出版社, 1994. 73-75
    1. Liu J, Xia W. Purification and characterization of a bifunctional enzyme with chitosanase and cellulase activity from commercial cellulose [J]. Biochem Eng J, 2006, 30:82-87
    2. Kittur F S, Kumar A, Gowda L R, etc. Chitosanolysis by a pectinase isozyme of Aspergillus niger—a non-specific activity [J]. Carbohydrate Polymers, 2003, 53: 191–196
    3. Hung T H, Fu J Y, Chiang C L, etc. Purification and characterization of hydrolase with chitinase and chitosanase activity from commercial stem bromelain [J]. Journal of Agricultural and Food Chemistry, 2002, 50: 4666-4673
    4. Fu J Y, Wu S M, Chang C T, etc. Characterization of three chitosanase isozymes isolated from a commercial crude porcine pepsin preparation [J]. Journal of Agricultural and Food Chemistry, 2003, 51: 1042-1048
    5. Chiang C L, Chang Y M, Chang C T, etc. Characterization of a chitosanase isolated from a commercial ficin preparation[J]. Journal of Agricultural and Food Chemistry, 2005, 53: 7579-7585
    6.陈来同.生化工艺学[M].北京:科学出版社,2004.108-121
    7.张玉奎.现代生物样品分离分析方法[M].北京:科学出版社,2003.40-72
    8.孙彦.生物分离工程[M].北京:化学工业出版社,1998,183-186
    9. Shin S S, Lee Y C, Lee C. The degradation of chitosan with the aid of lipase from Rhizopus japonicus for the production of soluble chitosan [J]. J Food Biochem, 2001,25:307-321
    10. Muzzarelli R A A, Xia W, Tomasetti, etc. Depolymerization of chitosan substituted chitosans with the aid of a wheat germ lipase preparation [J]. Enzyme and Microbial Technology, 1995, 17: 541-541
    11.张龙翔,张庭芳,李令媛.生化实验方法和技术(第二版)[M].北京:高等教育出版社, 1997. 460-467
    12.夏其昌.蛋白质化学研究技术与进展[M].北京:科学出版社, 1999.80-91
    13.姜锡瑞.酶制剂应用技术[M].北京:中国轻工业出版社,1996.271-274
    14.张龙翔,张庭芳,李令媛.生化实验方法和技术(第二版)[M].北京:高等教育出版社, 1997. 138-140
    15.夏其昌,曾嵘.蛋白质化学与蛋白质组学[M].北京:科学出版社,2004.6-7
    1.夏其昌.蛋白质化学研究技术与进展[M].北京:科学出版社, 1999.80-91
    2.姜涌明,戴祝英,陈俊明,等.分子酶学导论[M].北京:中国农业大学出版社, 2000. 75-84
    3. Melchior W B, Fahrney D. Ethoxyformylation of proteins. Reaction of ethoxyformic anhydride withα-chymotrypsin, pepsin and pancreatic ribbonuclease at pH4 [J]. Biochemistry, 1970, 9: 251-258
    4. Spanda T F, Witkop B. Determination of the typtophan content of protein with N-bromosuccinimide [J]. Methods in Enzymology, 1967, 11: 496-506
    5. Hoare D G, Koshland D E. A method for the quantitative modification and estimation of carboxylic acid groups in proteins [J]. Journal of Biological Chemistry, 1967, 242: 2447-2453
    6. James G T. Inactivation of the protease inhibitor phenylmethylsulfonyl fluoride in buffers [J]. Analytical Biochemistry, 1978, 86(2): 574-579
    7. Patthy L, Smith E L. Identification of functional arginine residues in ribbonuclease A and lysozyme [J]. The Journal of Biological Chemistry, 1975, 250(2): 565-569
    8. Riordan J F, Wacker W E, Vallee B L. N-Acetylimidazole: a reagent for determination of“free" tyrosyl residues of protein [J]. Biochemistry , 1965, 4 (9) : 1758-1765
    9. Ellman G L. A colorimetric method form determining low concentrations of mercaptans [J]. Archive of Biochemistry and biophysics, 1958, 74: 443-450
    10. Ellman G L. Tissue sulfhydryl groups [J]. Archives of Biochemistry and Biophysics, 1959, 82: 70-77
    11. Zhang R Q, Chen Q X, Zheng W Z, etc. Inhibition kinetics of green crab (Scylla serrata) alkaline phosphatase activity by dithiothreitol or 2-mercaptoethanol [J]. The International Journal of Biochmistry and Cell Biology, 2000, 32: 865-872
    12.张龙翔,张庭芳,李令媛.生化实验方法和技术(第二版)[M].北京:高等教育出版社, 1997. 138-140
    13.田耕,刘炯,晖蓝翎. NCBI网站及GenBank数据库概述[J].国外医学分子生物学分册, 2000, 22(5): 317-320
    14.马东晖,李小洁,马辉文.国际互联网上的NCBI分子生物学数据库简介[J].微生物学通报, 1999, 26(2): 150-153
    15. Machida M, Asai K, Sano M, etc. Genome sequencing and analysis of Aspergillus oryzae [J]. Nature, 2005, 438: 1157-1161
    16 . Blanke S R, Hager L P. Chemical Modification of Chloroperoxidase with Diethylpyrocarbonate: evidence for the presence of an essential histidine residue [J].The Journal of Biological Chemistry, 1990, 265(21): 12454-12461
    17. Levy H M, Leber P D, Ryan E M. Inactivation of myosin by 2,4-dinitrophenol and protection by adenosine triphosphate and other phosphate compounds [J], J Biol Chem, 1963, 238(11): 3654-3659
    18. Miles E W. Modification of histidyl residues in proteins by diethylpyrocarbonate [J]. Methods in Enzymology, 1977, 47: 431-442
    19.刘靖.纤维素酶水解壳聚糖的特性及机理研究[D]:[博士学位论文].无锡:江南大学, 2006
    20.陶慰孙.蛋白质分子基础[M].北京:高等教育出版社,1995.122-143
    21.周海梦,王洪睿.蛋白质化学修饰[M].北京:清华大学出版社, 1998. 40-41
    1. Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (1992). EC 3.2 Glycosidases. In: Webb, E. C., eds. Enzyme Nomenclature, San Diego: Academic Press. 1992. 346–369
    2. Henrissat B. A classification of glycosyl hydrolases based on amino-acid sequence similarities [J]. Biochem J, 1991,280: 309-316
    3. Henrissat B, Bairoch A. Updating the sequence-based classification of glycosyl hydrolases [J]. Biochem J,1996,316: 695-696
    4. Dahiya N, Tewari R, Hoondal G S. Biotechnological aspects of chitinolytic enzymes: a review [J]. Appl Microbiol Biotechnol, 71(6):773-782
    5. Cottaz S, Brasme B, Driguez H. A fluorescence-quenched chitopentaose for the study of endo-chitinases and chitobiosidases [J]. Eur J Biochem, 2000, 267:5593-5600
    6. Ike M, Ko Y, Yokoyama K, etc. Cellobiohydrolase I (Cel7A) from Trichoderma reesei has chitosanase activity [J]. Journal of Molecular Catalysis B: Enzymatic, 2007, 47: 159-163
    7. Henrissat B, Bairoch A. New families in the classification of glycosylhydrolases based on amino acid sequence similarities. Biochemical Journal, 1993, 293:781-788
    8.蒋挺大.甲壳素[M].北京:化学工业出版社, 2003.4-7
    9. Somashekar D, Joseph R. Chitosanase– Properties and applications: a review [J]. Bioresource Technology, 1996, 55: 35-45
    10.冯俊丽,朱旭芬.微生物几丁质酶的分子生物学研究[J].浙江大学学报(农业与生命科学版), 2004, 30(1): 102-108.
    11.张龙翔,张庭芳,李令媛.生化实验方法和技术(第二版)[M].北京:高等教育出版社, 1997. 460-467
    12.刘靖.纤维素酶水解壳聚糖的特性及机理研究[D]:[博士学位论文].无锡:江南大学,2006
    13.郭勇.酶工程原理与技术[M].北京高等教育出版社,2005.205-206
    14. Osswald W F, Shapiro J P, McDonald R E, etc. Some citrus chitinases also possess chitosanase activities [J]. Experientia, 1993, 49: 888-892
    15.孙雨安,王国庆,张应军,等.高效液相色谱-蒸发光散射检测法测定烟草中水溶性糖[J].分析科学学报,2004,20(5):531-533
    16 . Nanjo F, Katsumi R, Sakai K. Purification and characterization of an exo-β-D-glucosaminidase, a novel type of enzyme, from Nocardia orientalis [J]. Journal of Biological Chemistry, 1990, 265: 10088-10094
    17 Cote N, Fleury A, Dumont-Blanchette E, etc. Two exo-β-D-glucosaminidases/ exochitosanases from actinomycetes define a new subfamily within family 2 of glycoside hydrolases[J]. Biochem J, 2006, 394: 675–686
    18. Nogawa M, Takahashi H, Kashiwagi A, etc. Purification and characterization of exo-β-D-glucosaminidase from a cellulolytic fungus, Trichoderma reesei PC-3-7 [J]. Applied and Environmental Microbiology, 1998,64: 890-895
    19. Matsumura S, Yao E, Toshima K. One-step preparation of alkylβ-D-glucosaminide by the transglycosylation of chitosan and alcohol using purified exo-β-D-glucosaminidase. Biotechnology Letters, 1999, 21: 451-456
    20. Tanaka T, Fukui T, Atomi H, etc. Characterization of an exo-β-D-glucosaminidase involved in a novel chitinolytic pathway from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1[J]. Journal of Bacteriology, 2003, 185(17): 5175–5181
    21 . Jung W J, Kuk J H, Kim K Y, etc. Purification and characterization of exo-β-D-glucosaminidase from Aspergillus fumigatus S-26 [J]. Protein Expression and Purification, 2006, 45: 125-131
    22. Kim S Y, Shon D H, Lee K H. Purification and characteristics of two types of chitosanases from Aspergillus fumigatus KH-94 [J]. Journal of Microbiology and Biotechnology, 1998,8: 568-574
    23 . Ji J H, Yang J S, Hur J W. Purification and characterization of the exo-β-D-glucosaminidase from Aspergillus flavus IAM2044 [J]. Journal of Microbiology and Biotechnology, 2003,13, 269-275
    24. Zhang X Y, Dai A L, Zhang X K, etc. Purification and characterization of chitosanase and exo-β-D-glucosaminidase from a Koji Mold, Aspergillus oryzae IAM2660 [J]. Bioscience Biotechnology and Biochemistry, 2000,64: 1896-1902
    25. Chen X, Xia W, Yu X. Purification and characterization of two types of chitosanase from Aspergillus sp. CJ22-326 [J]. Food Research International, 2005, 38:315–322
    26. Kim P I, Kang T H, Chung K J. Purification of a constitutive chitosanase produced by Bacillus sp. MET 1299 with cloning and expression of the gene [J]. FEMS Microbiology Letters, 2004, 240:31–39
    27. Fukamizo T, Ohkawa T, Ikeda Y, etc. Specificity of chitosanase from Bacillus pumilus [J]. Biochim Biophys Acta, 1994, 1205: 183–188
    28 . Fukamizo T, Honda Y, Goto S, etc. Reaction mechanism of chitosanase from Streptomyces sp. N174 [J]. Biochem J,1995, 311: 377–383
    29. Izume M, Nagae S, Kawagishi H, etc. Action pattern of Bacillus sp. No. 7-M chitosanaseon partially N-acetylated chitosan [J]. Biosci Biotechnol Biochem,1992, 56: 448–453
    30. Mitsutomi M, OhtakaraA. Difference between microbial chitinase and chitosanase in the mode of action on partially N-acetylated chitosan [C] In: Brine C J, Sanford R A, Zikakis J P, Eds. Advances in Chitin and Chitosan. London: Elsevier,1992. 304–313
    31. Osswald W F, Shapiro J P, Doostdar H, etc. Identification and characterization of acidic hydrolases with chitinase and chitosanase activities from sweet orange callus tissue [J]. Plant Cell Physiol, 1994, 35:811-820
    32. Hung T H, Fu J Y, Chiang C L, etc. Purification and characterization of hydrolase with chitinase and chitosanase activity from commercial stem bromelain [J]. Journal of Agricultural and Food Chemistry, 2002, 50: 4666-4673
    33. Tanaka T, Fukui T, Fujiwara S, etc. Concerted action of diacetylchitobiose deacetylase and exo-β-D-glucosaminidase in a novel chitinolytic pathway in the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 [J]. The Journal of Biological Chemistry, 2004, 279: 30021–30027
    34. Kumar N N, Deobagkar D N. Multifunctional glucanases [J]. Biotechnology Advances, 1996, 14(1): 1-15

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