biochemical analysis of halophilic dehydrogenases altered by site directed mutagenesis
Tài liệu Báo cáo Y học: Insights into the reaction mechanism of Escherichia coli agmatinase by site-directed mutagenesis and molecular modelling ppt
... affected by the mutation, as revealed by the conservation of the whole topology of the active site, would explain the essentially unaltered interaction of the D153N variant with the metallic cofactor ... generated by a second round of PCR The expected mutation was confirmed by DNA sequence analysis That no unwanted mutations had been introduced during the mutagenesis process was verified by automated ... ligand-manganese distances RESULTS AND DISCUSSION By site- directed mutagenesis, a D153N mutant form of E coli agmatinase was obtained The mutant enzyme retained about 5% of wild-type activity and it was equally...
- 5
- 475
- 0
Báo cáo khoa học: Mapping of the active site of glutamate carboxypeptidase II by site-directed mutagenesis potx
... obtained from Perkin-Elmer (Boston, MA, USA) Site- directed mutagenesis Site- directed mutagenesis was carried out using the QuikChange Site- Directed Mutagenesis Kit (Stratagene, La Jolla, CA, USA) ... the active site and substrate binding cavity of GCPII [26,27] A more detailed insight into the active site was obtained by an analysis of crystal structures of the extracellular part of GCPII complexed ... to analyze the binding pocket of human GCPII using molecular modeling and sitedirected mutagenesis analysis Guided by the previously determined crystal structure of GCPII, we set out to complement...
- 11
- 484
- 0
Tài liệu Báo cáo khoa học: Identification of critical active-site residues in angiotensin-converting enzyme-2 (ACE2) by site-directed mutagenesis docx
... inhibitor This study provides the first investigation of the importance of key active -site residues of ACE2 through site- directed mutagenesis, with the aim of providing practical evidence for their role ... Fig Schematic view of the active site of ACE2 and tACE Binding interactions of the inhibitor (A) MLN-4760 at the active site of ACE2 and (B) lisinopril at the active site of tACE Hydrogen bonds ... result of replacing this single residue could not have 3517 Critical active -site residues of ACE2 been predicted simply by analysis of the active -site structure Further to this, the role of His505...
- 9
- 789
- 2
Tài liệu Báo cáo khoa học: Insights into the interaction of human arginase II with substrate and manganese ions by site-directed mutagenesis and kinetic studies Alteration of substrate specificity by replacement of Asn149 with Asp docx
... greatly altered by replacement of this residue with aspartate To the best of our knowledge, this is the first report in which the substrate specificity of arginase was altered by using sitedirected mutagenesis ... release of Mn2+B by EDTA during preparation of a substrate complex of Bacillus caldovelox arginase for crystallographic analysis [32] According to our present results, the catalytic activity of the ... detailed analysis of the effect was not performed, the inhibition by 20 mm agmatine was eliminated by saturation with l-arginine, indicating the competitive character of the inhibition produced by...
- 9
- 651
- 0
Tài liệu Báo cáo Y học: Study of substrate specificity of human aromatase by site directed mutagenesis pdf
... affinity of the substrates, particularly testosterone, and of the inhibitors by disfavoring the interaction of the pyridyl group with the heme This could be explained by the impact of the position of ... aromatase following site- directed mutagenesis Biochim Biophys Acta 1163, 195–200 52 Zhou, D.J., Korzekwa, K.R., Poulos, T & Chen, S.A (1992) A site- directed mutagenesis study of human placental ... aromatization of C19-androgens This is also supported by results obtained with D476A, D476K and D476L Moreover, because E302 is located on the opposite face of the active site, aromatization of nor-testosterone...
- 13
- 506
- 0
Báo cáo khoa học: Characterization of HbpR binding by site-directed mutagenesis of its DNA-binding site and by deletion of the effector domain pot
... footprints by HbpR [19] and are used as such also in other figures Sequence numbers refer to the locations of the transcriptional start site of hbpC (B) Alignments of the sequences of three HbpR-binding ... nucleotide motifs was characterized by site- directed mutagenesis and affinity binding by purified HbpR In several cases, DNaseI footprints were conducted to confirm the binding site contacts Additionally, ... of the hbpC promoter in Escherichia coli Results Mutagenesis of the HbpR-binding sites Sequence alignment of the UASs found in the HbpR operators in the hbpC and hbpD promoters defined a set of...
- 11
- 468
- 0
Báo cáo khoa học: Probing the catalytic potential of the hamster arylamine N-acetyltransferase 2 catalytic triad by site-directed mutagenesis of the proximal conserved residue, Tyr190 pot
... matched by that of the associated altered Asp122 To address this issue we carried out protein NMR structural studies of the most altered mutant, Y190A The results of those studies revealed an altered ... acetylation of NAT Site- directed mutagenesis of the hamster NAT2 Tyr190 to Phe (Y190F), to Ile (Y190I) and to Ala (Y190A), was carried out using the pPH70D vector and QuickChange site- directed mutagenesis ... and inactivation of hamster NAT1 by bromoacetamido derivatives of aniline and 2-aminouorene J Protein Chem 22, 631642 24 Dupret JM & Grant DM (1992) Site- directed mutagenesis of recombinant human...
- 14
- 350
- 0
Báo cáo khoa học: Functional significance of five noncanonical Ca2+-binding sites of human transglutaminase 2 characterized by site-directed mutagenesis potx
... serve as Ca2+-binding sites [19] The aim of the present study was to identify the exact Ca2+-binding sites of human TG2, by using sitedirected mutagenesis and targeting sites homologous to FXIIIa ... Ca2+-binding sites of TG2 ´ly R Kira et al Fig Multiple sequence alignment of Ca2+-binding sites of transglutaminases Sequence alignments of Ca2+-binding sites of TG2 compared with the other members of ... confirmed that each of the five mutagenized sites contributes to Ca2+ binding of TG2 It was also observed that disruption of one site by mutation leads to weaker ⁄ loss of binding to other sites, and this...
- 14
- 378
- 0
Báo cáo khoa học: Residues affecting the chloride regulation and substrate selectivity of the angiotensin-converting enzymes (ACE and ACE2) identified by site-directed mutagenesis pot
... CL2 sites of ACE and ACE2 were changed by site- directed mutagenesis, and the effects on chloride sensitivity, substrate selectivity and inhibitor potency were observed Results PCR mutagenesis of ... (A) Cleavage of angiotensin I by tACE variants (B) Cleavage of angiotensin I by ACE2 variants (C) Cleavage of angiotensin II by ACE2 variants Generation of product was determined by HPLC Numbers ... subjected to site- directed mutagenesis are shown in bold Cl) coordinating residues are shown in italic Cl) is unable to be bound by ACE2 at the CL2 site as a result of the side-chains of Glu398...
- 10
- 362
- 1
Báo cáo khoa học: Probing the unfolding region of ribonuclease A by site-directed mutagenesis potx
... To investigate the contribution of the two loop regions to the stability of the entire RNase A molecule, we replaced several amino-acid residues by site- directed mutagenesis (A20P, S21P, A20P/S21P, ... plasmid pBXR [19], a gift from R T Raines (University of Wisconsin, Madison, WI, USA), was modied by use of the QuikChangeTM site- directed mutagenesis kit (Stratagene) to obtain the mutations ... Phe46) Results Design of the RNase A variants Analysis by use of the program FIRST [30] (http:// rstweb.asu.edu/) indicates the highest exibility of the peptide backbone of native RNase A at the...
- 10
- 491
- 0
Báo cáo khoa học: Probing the mechanism of the bifunctional enzyme ketol-acid reductoisomerase by site-directed mutagenesis of the active site pot
... attempted to understand these roles by mutagenesis of E coli KARI FEBS Journal 272 (2005) 593–602 ª 2005 FEBS Mutagenesis of the active site of E coli KARI Most of the mutations abolish the overall ... properties of the acetohydroxy acid isomeroreductase of Salmonella typhimurium J Biol Chem 244, 1118–1127 601 Mutagenesis of the active site of E coli KARI Primerano DA & Burns RO (1983) Role of acetohydroxy ... organization of this enzyme is substantially different from that of the spinach enzyme with the active site constructed from two monomers of a dodecamer In contrast, the active site of spinach...
- 10
- 339
- 0
Báo cáo khoa học: Probing suggested catalytic domains of glycosyltransferases by site-directed mutagenesis Tobias Hefner and Joachim Stockigt ¨ ppt
... of the site- directed mutagenesis experiments presented here The question concerning the mechanism of one of the basic reactions in cells, the transfer of a sugar moiety during the formation of ... catalytic domains of NRD glycosyltransferases (Eur J Biochem 270) 537 the nucleophile We were able to prove for the first time the suggested model by site- directed mutagenesis of arbutin synthase ... exhibits the His-Glu site (Fig 2), proposed as a catalytic domain of general importance for the mechanism of sugar transfer The significance of this HisGlu site we also explored by an alignment based...
- 6
- 282
- 0
Báo cáo khoa học: Defining the QP-site of Escherichia coli fumarate reductase by site-directed mutagenesis, fluorescence quench titrations and EPR spectroscopy doc
... region of FrdB on the cytoplasmic side of the membrane The other site, the ˚ QD site (the distal Q -site) is located approximately 25 A from the QP site on the opposite (periplasmic) side of the ... polar QB site (equivalent to the QP site) , and an apolar QA site (equivalent to the QD site) [13–15] Investigation of the steadystate kinetics of quinol-dependent fumarate reduction by FrdABCD ... transfer subunit of DmsABC (DmsB) contains four [4Fe-4S] clusters, and one of these can be changed to a [3Fe-4S] cluster by site- directed mutagenesis (in a DmsB-C102S mutant) [29] Treatment of this mutant...
- 14
- 359
- 0
Báo cáo khoa học: Probing the determinants of coenzyme specificity in Peptostreptococcus asaccharolyticus glutamate dehydrogenase by site-directed mutagenesis potx
... pattern of a glutamate residue at the P7 position This implies that the two enzymes distinguish the cofactors in different ways [3] In the present study, we have investigated, by means of site- directed ... opportunity to explore the generality of such specificity rules with a number of different dehydrogenases [6–8] A Rossmann fold is also typical of l-glutamate dehydrogenases (GDH) (EC 1.4.1.2–4) ... via varying degrees of dual specificity to extreme NADP+ specificity at the other end An alignment of sequences by Teller et al [12] demonstrated that the GDHs differ from other dehydrogenases in...
- 8
- 375
- 0
Báo cáo khoa học: The phosphate site of trehalose phosphorylase from Schizophyllum communeprobed by site-directed mutagenesis and chemical rescue studies pptx
... phosphate site of Schizophyllum commune trehalose phosphorylase scanning mutagenesis of the active site of trehalose phosphorylase [16] and report on results of steadystate kinetic analysis and ... K512A by guanidine (10200 mm) was observed Addition of 200 mm of NaCl did not alter the activity of either one of the site- directed mutants These results Fig Functional complementation of mutant ... basal rate of hydrolysis of a,a-trehalose by K512A was enhanced signicantly (approximately 1.6-fold) in the presence of 50 mm of phosphate By contrast to the clear inhibitory effect of vanadate...
- 11
- 428
- 0
Báo cáo khoa học: Binding areas of urokinase-type plasminogen activator– plasminogen activator inhibitor-1 complex for endocytosis receptors of the low-density lipoprotein receptor family, determined by site-directed mutagenesis doc
... latent PAI-1 in the medium by the use of denaturation with SDS and refolding by removing the SDS by addition of an excess of BSA 125I-uPAPAI-1 complexes were prepared by adding 125I-uPA to the ... formation as the result of complete cleavage of the P1P1Â bond or by insertion of the uncleaved RCL in latent PAI-1 [15] Unfortunately, there is no X-ray crystal structure analysis of any receptorproteaseinhibitor ... Fig The 3D structures of PAI-1 and uPA The gure shows ribbon diagrams of the structure of the active conformation of PAI-1 [53] (pdb le 1B3K) and the structure of the SPD of uPA [27] (pdb le 1LMW)...
- 17
- 269
- 0
Tài liệu Báo cáo khoa học: nsights into the reaction mechanism of glycosyl hydrolase family 49 Site-directed mutagenesis and substrate preference of isopullulanase doc
... a-(1fi4)-linked glucose units of pullulan (Fig 4A) IPU is an anomer-inverting enzyme Comparison of the active sites of the model of IPU and Dex49A The active site structures of the model of IPU (Fig 4A) and ... Trp425 of Dex49A, which is the corresponding residue of Trp402 of IPU, is reportedly located in the vicinity of the active site and could form a binding site for a glucosyl unit in subsite )1 ... Dijkstra, B.W (1999) 1.68-A crystal structure of endopolygalacturonase II from Aspergillus niger and identification of active site residues by site- directed mutagenesis J Biol Chem 274, 30474–30480...
- 8
- 551
- 0
Báo cáo khoa học: Tracking interactions that stabilize the dimer structure of starch phosphorylase from Corynebacterium callunae Roles of Arg234 and Arg242 revealed by sequence analysis and site-directed mutagenesis doc
... argininesÕ of StP were selected as candidates to be replaced by alanine-scanning site- directed mutagenesis We have assessed the role of each arginine for oxyanion-dependent stability of the StP ... destabilizing in unligated StP, site- directed mutagenesis of the side chain of Arg234 into the methyl side chain of alanine did not diminish the stabilizing effect of sulfate binding in comparison ... the catalytic site and the PLP binding site of StP are virtually identical to the corresponding sites in rmGP and EcMalP By contrast, the regulatory sites of rmGP are almost completely lost in...
- 11
- 444
- 0
A discourse analysis of english speeches delivered by guest speakers at graduation ceremonies in US colleges and universities
... confined to the investigation of some discourse features of graduation speeches The scope of the study is just limited to the analysis of formal speeches delivered by guest speakers at graduation ... BACKGROUND 2.2.1 Text 2.2.1.1 Concept of Text 2.2.1.2 Features of Text 2.2.2 Discourse & Discourse Analysis 2.2.2.1 Concept of Discourse 2.2.2.2 Concept of Discourse Analysis 2.2.3 Written and Spoken ... The focus of the study is on the discourse analysis of EGSs so the concept of discourse analysis, text, cohesion, and coherence are included in this chapter I have chosen the viewpoints of some...
- 13
- 839
- 2
An analysis of errors commonly committed by high school students in using english questions
... The error analysis supplanted Contrastive Analysis and became a recognized part of Applied Linguistics owing to the work of Corder (1967) who saw it from a different point of view Error analysis ... valuable aspects of contrastive analysis have been incorporated into the study of language transfer, it was unable to predict a great majority of errors 28 A key finding of error analysis has been ... error analysis, errors in language learning are not caused by the interference of learners’ mother tongue but by learners’ learning strategies Corder proposes that the process of error analysis...
- 117
- 828
- 4
Tìm thêm: xác định các nguyên tắc biên soạn khảo sát các chuẩn giảng dạy tiếng nhật từ góc độ lí thuyết và thực tiễn khảo sát chương trình đào tạo của các đơn vị đào tạo tại nhật bản khảo sát chương trình đào tạo gắn với các giáo trình cụ thể xác định thời lượng học về mặt lí thuyết và thực tế tiến hành xây dựng chương trình đào tạo dành cho đối tượng không chuyên ngữ tại việt nam điều tra đối với đối tượng giảng viên và đối tượng quản lí khảo sát thực tế giảng dạy tiếng nhật không chuyên ngữ tại việt nam nội dung cụ thể cho từng kĩ năng ở từng cấp độ xác định mức độ đáp ứng về văn hoá và chuyên môn trong ct các đặc tính của động cơ điện không đồng bộ đặc tuyến hiệu suất h fi p2 đặc tuyến mômen quay m fi p2 đặc tuyến dòng điện stato i1 fi p2 động cơ điện không đồng bộ một pha sự cần thiết phải đầu tư xây dựng nhà máy thông tin liên lạc và các dịch vụ phần 3 giới thiệu nguyên liệu chỉ tiêu chất lượng theo chất lượng phẩm chất sản phẩm khô từ gạo của bộ y tế năm 2008 chỉ tiêu chất lượng 9 tr 25