期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
耐热异淀粉酶的高效表达及其在麦芽糖浆制备中的作用 被引量:3
1
作者 方安然 牛丹丹 +3 位作者 乔舰 吴海洋 董自星 路福平 《食品与发酵工业》 CAS CSCD 北大核心 2016年第7期23-29,共7页
淀粉酶法制备高麦芽糖浆工艺中,淀粉液化酶、脱支酶以及β-淀粉酶不可或缺,其中脱支酶是决定淀粉转化为麦芽糖的转化率高低的关键因素。在工业上常用的两种脱支酶中,异淀粉酶比普鲁兰酶能更好地协助β-淀粉酶水解淀粉生成麦芽糖。首... 淀粉酶法制备高麦芽糖浆工艺中,淀粉液化酶、脱支酶以及β-淀粉酶不可或缺,其中脱支酶是决定淀粉转化为麦芽糖的转化率高低的关键因素。在工业上常用的两种脱支酶中,异淀粉酶比普鲁兰酶能更好地协助β-淀粉酶水解淀粉生成麦芽糖。首先通过PCR扩增获得异淀粉酶的编码基因iso并克隆入表达载体pHY—WZX,在枯草芽胞杆菌1A717中获得重组质粒pHY—ISO,将构建好的重组质粒电转化入地衣芽孢杆菌D402中,其摇瓶发酵酶活力达330U/mL,实现了异淀粉酶的异源高效表达。基本酶学特征分析表明:该重组酶适宜反应条件为50~55℃,pH6.5~9.0;K+、Ca2+、Mg2+对酶活有促进作用,其他离子或化合物强烈抑制酶活。HPLC分析表明,该重组异淀粉酶与普鲁兰酶相比,更有助于极高麦芽糖浆的制备。最后通过在线软件对该酶进行同源结构模拟和分析,进一步确定其为异淀粉酶,为后续对其进行分子改造奠定了基础。 展开更多
关键词 异淀粉酶 地衣芽胞杆菌 高效表达 麦芽糖浆生产 同源结构模拟
下载PDF
Molecular dynamics simulation of the interactions between EHD1 EH domain and multiple peptides 被引量:1
2
作者 Hua YU Mao-jun WANG +2 位作者 Nan-xia XUAN Zhi-cai SHANG Jun WU 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2015年第10期883-896,共14页
Objective: To provide essential information for peptide inhibitor design, the interactions of Eps15 homology domain of Eps15 homology domain-containing protein 1 (EHD1 EH domain) with three peptides containing NPF ... Objective: To provide essential information for peptide inhibitor design, the interactions of Eps15 homology domain of Eps15 homology domain-containing protein 1 (EHD1 EH domain) with three peptides containing NPF (asparagine-proline-phenylalanine), DPF (aspartic acid-proline-phenylalanine), and GPF (glycine-proline-phenylalanine) motifs were deciphered at the atomic level. The binding affinities and the underlying structure basis were investigated. Methods: Molecular dynamics (MD) simulations were performed on EHD1 EH domain/peptide complexes for 60 ns using the GROMACS package. The binding free energies were calculated and decomposed by molecular mechanics/ generalized Born surface area (MM/GBSA) method using the AMBER package. The alanine scanning was performed to evaluate the binding hot spot residues using FoldX software. Results: The different binding affinities for the three peptides were affected dominantly by van der Waals interactions. Intermolecular hydrogen bonds provide the struc- tural basis of contributions of van der Waals interactions of the flanking residues to the binding. Conclusions: van der Waals interactions should be the main consideration when we design peptide inhibitors of EHD1 EH domain with high affinities. The ability to form intermolecular hydrogen bonds with protein residues can be used as the factor for choosing the flanking residues. 展开更多
关键词 Binding affinity EHD1 EH domain Molecular dynamics simulation Inhibitor design PEPTIDE
原文传递
Predicting hiCE inhibitors based upon pharmacophore models derived from the receptor and its ligands 被引量:1
3
作者 ZHANG GuoDong GE Hu +1 位作者 GU Qiong XU Jun 《Science China Chemistry》 SCIE EI CAS 2013年第10期1402-1412,共11页
Human intestinal carboxyl esterase (hiCE) is a drug target for ameliorating irinotecan-induced diarrhea. By reducing irinotecan- induced diarrhea, hiCE inhibitors can improve the anti-cancer efficacy of irinotecan. ... Human intestinal carboxyl esterase (hiCE) is a drug target for ameliorating irinotecan-induced diarrhea. By reducing irinotecan- induced diarrhea, hiCE inhibitors can improve the anti-cancer efficacy of irinotecan. To find effective hiCE inhibitors, a new virtual screening protocol that combines pharmacophore models derived from the hiCE structure and its ligands has been pro- posed. The hiCE structure has been constructed through homology techniques using hCESI's crystal structure. The hiCE structure was optimized via molecular dynamics simulations with the most known active hiCE inhibitors docked into the structure. An optimized pharmacophore, derived from the receptor, was then generated. A ligand-based pharmacophore was also generated from a larger set of known hiCE inhibitors. The final hiCE inhibitor predictions were based upon the virtual screening hits from both ligand-based and receptor-based pharmacophore models. The hit rates from the ligand-based and receptor-based pharmacophore models are 88% and 86%, respectively. The final hit rate is 94%. The two models are highly consistent with one another (85%). This proves that both models are reliable. 展开更多
关键词 carboxyl esterase PHARMACOPHORE virtual screening ANTI-CANCER
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部