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采用固定化洋葱假单胞菌(PC)脂肪酶为催化剂,研究了在氯仿和四氢呋喃(THF)中不同摩尔比的聚(丁二酸丁二醇-co-丁二酸己二醇酯)(PBSH)的酶促降解规律及其差异性.通过PBSH降解前后的相对分子质量变化、降解产物的MALDI-TOF-MS分析研究了共聚酯降解规律,并以分子动力学(MD)及分子对接模拟分别研究了PC酶的溶剂效应及酶与底物的结合机制.研究结果表明,PC酶在2种溶剂中均可催化PBSH降解,但在氯仿中酶的活性较大,PBSH降解率大.分子动力学模拟数据表明,在THF中,PC酶整体氨基酸残基的涨落比氯仿中大,且THF会进入酶活性口袋中与催化残基Ser87结合,破坏了催化残基Ser87和His286之间的相互作用.分子对接结果分析发现,含丁二酸己二醇酯(HS)单元底物与PC酶活性位点的对接比含丁二酸丁二醇酯(BS)单元的更为稳定.
Using immobilized lipase from Pseudomonas cepacia (PC) as a catalyst, the effects of different molar ratios of poly (butylene succinate-co-hexanediol adipate) in chloroform and tetrahydrofuran (THF) PBSH), and their differences.According to the molecular weight changes of PBSH before and after degradation, the degradation of copolyester by MALDI-TOF-MS analysis of degradation products, molecular docking (MD) and molecular docking The solvent effect of PC enzyme and the binding mechanism between enzyme and substrate were studied respectively.The results showed that PCH could catalyze the degradation of PBSH in both solvents, but the activity of enzyme in chloroform was larger and the degradation rate of PBSH was larger. Molecular dynamics simulations showed that the global amino acid residues in PC enzyme fluctuated more than chloroform in THF and THF was incorporated into the enzymatic pocket to bind to the catalytic residue Ser87 and disrupted the catalytic residues Ser87 and His286 The results of molecular docking showed that the docking of HS with succinate units was more stable than that with succinate butanediol (BS) units.