A A Hambardzumyan, A V Mkhitaryan, A M Paloyan, S A Dadayan, A S Saghyan
{"title":"[Catalytic properties of aminoacylase of strain Rhodococcus armeniensis AM6.1].","authors":"A A Hambardzumyan, A V Mkhitaryan, A M Paloyan, S A Dadayan, A S Saghyan","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>Studies of substrate specificity revealed that the D-aminoacylase of Rhodococcus armeniensis AM6.1 strain exhibits absolute stereospecificity to the D-stereoisomers of N-acetyl-amino acids. The enzyme is the most active reacted with N-acetyl-D-methionine, as well as with aromatic and hydrophobic N-acetylamino acids and interacts weakly with the basic substrates. It is practically not reacted with acidic and hydrophilic N-acetyl-amino acids. Michaelis constants (K m) and maximum reaction velocities (V max) were calculated, using linear regression analysis, for the following substrates: N-acetyl-D-methionine, N-acetyl-D-alanine, N-acetyl-D-phenylalanine, N-acetyl-D-tyrosine, N-acetyl-D-valine, N-acetyl-D-oxyvaline, N-acetyl- D-leucine. Substrate inhibition of D-aminoacylase was displayed with N-acetyl-D-leucine (K s = 35.5 ± 28.3 mM) and N-acetyl-DL-tyrosine (K s = 15.8 ± 4.5 mM). Competitive inhibition of the enzyme with product–acetic acid (K i = 104.7 ± 21.7 mM, K m = 2.5 ± 0.5 mM, V max = 25.1 ± 1.5 U/mg) was observed.</p>","PeriodicalId":20415,"journal":{"name":"Prikladnaia biokhimiia i mikrobiologiia","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2016-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Prikladnaia biokhimiia i mikrobiologiia","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Studies of substrate specificity revealed that the D-aminoacylase of Rhodococcus armeniensis AM6.1 strain exhibits absolute stereospecificity to the D-stereoisomers of N-acetyl-amino acids. The enzyme is the most active reacted with N-acetyl-D-methionine, as well as with aromatic and hydrophobic N-acetylamino acids and interacts weakly with the basic substrates. It is practically not reacted with acidic and hydrophilic N-acetyl-amino acids. Michaelis constants (K m) and maximum reaction velocities (V max) were calculated, using linear regression analysis, for the following substrates: N-acetyl-D-methionine, N-acetyl-D-alanine, N-acetyl-D-phenylalanine, N-acetyl-D-tyrosine, N-acetyl-D-valine, N-acetyl-D-oxyvaline, N-acetyl- D-leucine. Substrate inhibition of D-aminoacylase was displayed with N-acetyl-D-leucine (K s = 35.5 ± 28.3 mM) and N-acetyl-DL-tyrosine (K s = 15.8 ± 4.5 mM). Competitive inhibition of the enzyme with product–acetic acid (K i = 104.7 ± 21.7 mM, K m = 2.5 ± 0.5 mM, V max = 25.1 ± 1.5 U/mg) was observed.
底物特异性研究表明，亚美尼亚红球菌AM6.1菌株的d -氨基酰化酶对n -乙酰基氨基酸的d -立体异构体具有绝对的立体特异性。该酶与n -乙酰- d -蛋氨酸以及芳香和疏水的n -乙酰氨基酸反应最活跃，与碱性底物相互作用弱。它几乎不与酸性和亲水的n -乙酰基氨基酸反应。对n -乙酰- d -蛋氨酸、n -乙酰- d -丙氨酸、n -乙酰- d -苯丙氨酸、n -乙酰- d -酪氨酸、n -乙酰- d -缬氨酸、n -乙酰- d -oxyvaline、n -乙酰- d -亮氨酸进行线性回归分析，计算Michaelis常数(K m)和最大反应速度(V max)。n -乙酰- d -亮氨酸(K s = 35.5±28.3 mM)和n -乙酰- dl -酪氨酸(K s = 15.8±4.5 mM)对d -氨基酰化酶有底物抑制作用。产物乙酸对该酶有竞争性抑制作用(ki = 104.7±21.7 mM, km = 2.5±0.5 mM, vmax = 25.1±1.5 U/mg)。
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