Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology最新文献_第5页

Lys40 but not Arg143 influences selectivity of angiotensin conversion by human α-chymase Lys40影响血管紧张素转化α-酶的选择性，而Arg143不影响

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00224-8

Diego J. Muilenburg, Wilfred W. Raymond, Paul J. Wolters, George H. Caughey

{"title":"Lys40 but not Arg143 influences selectivity of angiotensin conversion by human α-chymase","authors":"Diego J. Muilenburg, Wilfred W. Raymond, Paul J. Wolters, George H. Caughey","doi":"10.1016/S0167-4838(02)00224-8","DOIUrl":"10.1016/S0167-4838(02)00224-8","url":null,"abstract":"<div>Human α-chymase is an efficient angiotensin (AT) converting enzyme, selectively hydrolyzing AT I at Phe8 to generate bioactive AT II, which can promote cardiac hypertrophy, vascular stenosis, and hypertension. Some related enzymes, such as rat β-chymase 1, are much less selective, destroying AT by cleaving at Tyr4. Comparisons of chymase structure and activity led to speculation that interaction between AT and the side chain of Lys40 or Arg143 accounts for the human enzyme’s marked preference for Phe8 over Tyr4. To test these hypotheses, we compared AT hydrolysis by wild-type chymase with that by mutants changing Lys40 or Arg143 to neutral residues. Lys40 was exchanged for alanine, the residue found in canine α- and rat β-chymase 1, the latter being dramatically less selective for hydrolysis at Phe8. Arg143 was exchanged for glutamine found in rat β-chymase 1. The Lys40Ala mutant is a dog-like enzyme retaining strong preference for Phe8 but with Tyr4 hydrolytic rates enhanced 16-fold compared to wild-type human enzyme. Thus, of 40 residues mismatched between dog and human enzymes, a single residue accounts for most of the difference in specificity between them. The Arg143Gln mutant, contrary to prediction, remains highly Phe8-selective. Therefore, Lys40, but not Arg143, contributes to human chymase’s remarkable preference for AT II generation over destruction.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(02)00224-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79622609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 26

Kinetic parameters and mode of action of the cellobiohydrolases produced by Talaromyces emersonii 墨氏Talaromyces emersonii纤维素生物水解酶的动力学参数和作用方式

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(01)00308-9

Maria G Tuohy , Daniel J Walsh , Patrick G Murray , Marc Claeyssens , Michelle M Cuffe , Angela V Savage , Michael P Coughlan

{"title":"Kinetic parameters and mode of action of the cellobiohydrolases produced by Talaromyces emersonii","authors":"Maria G Tuohy , Daniel J Walsh , Patrick G Murray , Marc Claeyssens , Michelle M Cuffe , Angela V Savage , Michael P Coughlan","doi":"10.1016/S0167-4838(01)00308-9","DOIUrl":"10.1016/S0167-4838(01)00308-9","url":null,"abstract":"<div>Three forms of cellobiohydrolase (EC 3.2.1.91), CBH IA, CBH IB and CBH II, were isolated to apparent homogeneity from culture filtrates of the aerobic fungus Talaromyces emersonii. The three enzymes are single sub-unit glycoproteins, and unlike most other fungal cellobiohydrolases are characterised by noteworthy thermostability. The kinetic properties and mode of action of each enzyme against polymeric and small soluble oligomeric substrates were investigated in detail. CBH IA, CBH IB and CBH II catalyse the hydrolysis of microcrystalline cellulose, albeit to varying extents. Hydrolysis of a soluble cellulose derivative (CMC) and barley 1,3;1,4-β-D-glucan was not observed. Cellobiose (G2) is the main reaction product released by CBH IA, CBH IB, and CBH II from microcrystalline cellulose. All three CBHs are competitively inhibited by G2; inhibition constant values (Ki) of 2.5 and 0.18 mM were obtained for CBH IA and CBH IB, respectively (4-nitrophenyl-β-cellobioside as substrate), while a Ki of 0.16 mM was determined for CBH II (2-chloro-4-nitrophenyl-β-cellotrioside as substrate). Bond cleavage patterns were determined for each CBH on 4-methylumbelliferyl derivatives of β-cellobioside and β-cellotrioside (MeUmbGn). While the Tal. emersonii CBHs share certain properties with their counterparts from Trichoderma reesei, Humicola insolens and other fungal sources, distinct differences were noted.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(01)00308-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82363854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 81

Preliminary crystallographic studies of Limulus polyphemus hemocyanin subunits IIIa, IIIb and IV 鲎血青素亚基IIIa、IIIb和IV的结晶学初步研究

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00231-5

Shenping Liu , Karen A. Magnus

引用次数: 2

Cumulative Contents 累积的内容

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00300-X

引用次数: 0

Kynurenine formamidase: determination of primary structure and modeling-based prediction of tertiary structure and catalytic triad1 犬尿氨酸甲酰胺酶:一级结构的测定和基于模型的三级结构和催化三联体预测1

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00232-7

Michael K. Pabarcus , John E. Casida

{"title":"Kynurenine formamidase: determination of primary structure and modeling-based prediction of tertiary structure and catalytic triad1","authors":"Michael K. Pabarcus , John E. Casida","doi":"10.1016/S0167-4838(02)00232-7","DOIUrl":"10.1016/S0167-4838(02)00232-7","url":null,"abstract":"<div>Kynurenine formamidase (KFase) (EC 3.5.1.9) hydrolyzes N-formyl-l-kynurenine, an obligatory step in the conversion of tryptophan to nicotinic acid. Low KFase activity in chicken embryos, from inhibition by organophosphorus insecticides and their metabolites such as diazoxon, leads to marked developmental abnormalities. While KFase was purportedly isolated previously, the structure and residues important for catalysis and inhibition were not established. KFase was isolated here from mouse liver cytosol by (NH4)2SO4 precipitation and three FPLC steps (resulting in 221-fold increase in specific activity for N-formyl-l-kynurenine hydrolysis) followed by conversion to [3H]diethylphosphoryl-KFase and finally isolation by C4 reverse-phase high-performance liquid chromatography. Determination of tryptic fragment amino acid sequences and cDNA cloning produced a new 305-amino-acid protein sequence. Although an amidase by function, the primary structure of KFase lacks the amidase signature sequence and is more similar to esterases and lipases. Sequence profile analysis indicates KFase is related to the esterase/lipase/thioesterase family containing the conserved active-site serine sequence GXSXG. The α/β-hydrolase fold is suggested for KFase by its primary sequence and predicted secondary conformation. A three-dimensional model based on the structures of homologous carboxylesterase EST2 and brefeldin A esterase implicates Ser162, Asp247 and His279 as the active site triad.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(02)00232-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77198089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 37

Microcalorimetric study of elongation factor Tu from Thermus thermophilus in nucleotide-free, GDP and GTP forms and in the presence of elongation factor Ts 伸长因子Tu在无核苷酸、GDP和GTP形式及伸长因子Ts存在下的微量热分析研究

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00225-X

Erik Sedlák , Mathias Sprinzl , Norbert Grillenbeck , Marián Antalı́k

引用次数: 5

Effects of guanidine hydrochloride and high pressure on subsite flexibility of β-amylase 盐酸胍和高压对β-淀粉酶亚位柔韧性的影响

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00217-0

Naoki Tanaka, Sachie Kajimoto, Daisuke Mitani, Shigeru Kunugi

{"title":"Effects of guanidine hydrochloride and high pressure on subsite flexibility of β-amylase","authors":"Naoki Tanaka, Sachie Kajimoto, Daisuke Mitani, Shigeru Kunugi","doi":"10.1016/S0167-4838(02)00217-0","DOIUrl":"10.1016/S0167-4838(02)00217-0","url":null,"abstract":"<div>We investigated the effects of guanidine hydrochloride (GuHCl) and high pressure on the conformational flexibility of the active site of sweet potato β-amylase by monitoring the sulfhydryl reaction and the enzymatic activity. The reactivity of Cys345 at the active site, one of six inert half cystine residues of this enzyme, was enhanced by GuHCl at concentrations below 0.5 M. A GuHCl-induced change of the active site was also observed through an intensity change in the near-UV circular dichroism (CD) spectrum. On the other hand, the native conformation of sweet potato β-amylase observed through fluorescence polarization, far-UV CD spectrum and intrinsic fluorescence was not influenced by GuHCl at concentrations below 0.5 M. Therefore, Cys345 reaction caused by GuHCl was due to an alteration of the local conformation of the active site. GuHCl-induced reaction of Cys345, located in the vicinity of subsites 3 and 4, is attributed to enhanced subsite flexibility, which is responsible for substrate slipping in a single-chain attack mechanism. Due to the flexible conformation, the local region of the subsite is more susceptible to GuHCl perturbation than the molecule overall. The enzymatic activity of sweet potato β-amylase was reversibly inhibited by GuHCl at concentrations below 0.5 M, and kinetic analysis of the enzymatic mechanism showed that GuHCl decreases the kcat value. High pressure below 400 MPa also inactivated sweet potato β-amylase with an increase in Cys345 reactivity. These findings indicated that excessively enhanced subsite flexibility reduced the enzymatic activity of sweet potato β-amylase.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(02)00217-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74882223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

The blockage of the high-affinity lysine binding sites of plasminogen by EACA significantly inhibits prourokinase-induced plasminogen activation EACA阻断纤溶酶原高亲和赖氨酸结合位点，可显著抑制脯氨酸激酶诱导的纤溶酶原活化

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00233-9

Ziyong Sun , Yu-hong Chen , Ping Wang , Jing Zhang , Victor Gurewich , Peixiang Zhang , Jian-Ning Liu

{"title":"The blockage of the high-affinity lysine binding sites of plasminogen by EACA significantly inhibits prourokinase-induced plasminogen activation","authors":"Ziyong Sun , Yu-hong Chen , Ping Wang , Jing Zhang , Victor Gurewich , Peixiang Zhang , Jian-Ning Liu","doi":"10.1016/S0167-4838(02)00233-9","DOIUrl":"10.1016/S0167-4838(02)00233-9","url":null,"abstract":"<div>Prourokinase-induced plasminogen activation is complex and involves three distinct reactions: (1) plasminogen activation by the intrinsic activity of prourokinase; (2) prourokinase activation by plasmin; (3) plasminogen activation by urokinase. To further understand some of the mechanisms involved, the effects of epsilon-aminocaproic acid (EACA), a lysine analogue, on these reactions were studied. At a low range of concentrations (10–50 μM), EACA significantly inhibited prourokinase-induced (Glu-/Lys-) plasminogen activation, prourokinase activation by Lys-plasmin, and (Glu-/Lys-) plasminogen activation by urokinase. However, no inhibition of plasminogen activation by Ala158-prourokinase (a plasmin-resistant mutant) occurred. Therefore, the overall inhibition of EACA on prourokinase-induced plasminogen activation was mainly due to inhibition of reactions 2 and 3, by blocking the high-affinity lysine binding interaction between plasmin and prourokinase, as well as between plasminogen and urokinase. These findings were consistent with kinetic studies which suggested that binding of kringle 1–4 of plasmin to the N-terminal region of prourokinase significantly promotes prourokinase activation, and that binding of kringle 1–4 of plasminogen to the C-terminal lysine158 of urokinase significantly promotes plasminogen activation. In conclusion, EACA was found to inhibit, rather than promote, prourokinase-induced plasminogen activation due to its blocking of the high-affinity lysine binding sites on plasmin(ogen).</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(02)00233-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73164146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 77

Effect of dimethyl sulfoxide on the structure and the functional properties of horseradish peroxidase as observed by spectroscopy and cyclic voltammetry 用光谱法和循环伏安法研究了二甲亚砜对辣根过氧化物酶结构和功能性质的影响

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00220-0

Roberto Santucci , Enzo Laurenti , Federica Sinibaldi , Rosa Pia Ferrari

{"title":"Effect of dimethyl sulfoxide on the structure and the functional properties of horseradish peroxidase as observed by spectroscopy and cyclic voltammetry","authors":"Roberto Santucci , Enzo Laurenti , Federica Sinibaldi , Rosa Pia Ferrari","doi":"10.1016/S0167-4838(02)00220-0","DOIUrl":"10.1016/S0167-4838(02)00220-0","url":null,"abstract":"<div>Electrochemical biosensors have found wide application in food and clinical areas, as well as in environmental field. A large number of articles focused on horseradish peroxidase (HRP)-based biosensors have been published in the last decade, due to the capability of HRP to quantitatively detect the presence of hydrogen peroxide produced in a reaction. At present a large body of multi-enzymatic amperometric biosensors are realized by entrapping HRP together with other enzymes into a polymeric matrix; these systems represent a promising example of simple, low-cost electrochemical tools for the analysis of bioanalytes in solution, such as glucose, choline and cholesterol. Due to the fact that polymers used for HRP entrapping are soluble in organic solvents and that many solvents are strong denaturants of aquo-soluble proteins, in this paper we investigate (in particular, by circular dichroism and electron paramagnetic spectroscopies) the effect of dimethyl sulfoxide, one of the organic solvents employed for polymer solubilization, on the structure and the functionality of HRP, in order to determine the effect induced by the solvent concentration on the structure and activity of the hemoprotein. This is relevant for basic and applied biochemistry, HRP being largely employed in bioinorganic chemistry and sensor area.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(02)00220-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90807973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 37

Novel anti-inflammatory compounds from Rubus sieboldii, triterpenoids, are inhibitors of mammalian DNA polymerases 从三叶草中提取的新型抗炎化合物三萜是哺乳动物DNA聚合酶的抑制剂

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-29 DOI: 10.1016/S0167-4838(02)00227-3

Chikako Murakami , Kiyomi Ishijima , Mitsuru Hirota , Kengo Sakaguchi , Hiromi Yoshida , Yoshiyuki Mizushina

{"title":"Novel anti-inflammatory compounds from Rubus sieboldii, triterpenoids, are inhibitors of mammalian DNA polymerases","authors":"Chikako Murakami , Kiyomi Ishijima , Mitsuru Hirota , Kengo Sakaguchi , Hiromi Yoshida , Yoshiyuki Mizushina","doi":"10.1016/S0167-4838(02)00227-3","DOIUrl":"10.1016/S0167-4838(02)00227-3","url":null,"abstract":"<div>Two anti-inflammatory triterpenoids, tormentic acid (TA) and euscaphic acid (EA), were found from the plant Rubus sieboldii. These triterpenoids showed an inhibitory effect against enzymes involved in replication, such as calf DNA polymerase α (pol α) and rat DNA polymerase β (pol β). The IC50 values of TA and EA were 37 and 61 μM for pol α and 46 and 108 μM for pol β, respectively. However, TA and EA did not influence the activities of plant DNA polymerases, DNA primase, human immunodeficiency virus type-1 reverse transcriptase, terminal deoxynucleotidyl transferase, any of the prokaryotic DNA polymerases or DNA and RNA metabolic enzymes tested. TA and EA could prevent the growth of BALL-1 cancer cells, and the LD50 values were 11 and 48 μM, respectively. The cells were halted at G1 phase in the cell cycle. The mode of action of the triterpenoids against anti-inflammatory activity and their relationships to the DNA polymerase inhibitory activity and cell growth inhibition were discussed.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(02)00227-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90000536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 28