The purification and characterization of delta 5-3-ketosteroid isomerase from Pseudomonas putida, a cysteine-containing isomerase.
The purification and characterization of delta 5-3-ketosteroid isomerase from Pseudomonas putida, a cysteine-containing isomerase.
复制标题
恶臭假单胞菌 δ 5-3-酮类固醇异构酶（一种含半胱氨酸的异构酶）的纯化和表征。
DOI：
--
复制
发表时间：
1980
影响因子：
4.8
通讯作者：
W. Benisek
中科院分区：
文献类型：
--
作者：
S. B. Smith;J. Richards;W. Benisek
从B型恶臭假单胞菌中分离纯化出一种β-5-3-酮类固醇异构酶(EC5.3.3.1)。这种先前未被描述的类固醇异构酶类似于从假单胞菌酮(Talalay，P.和Wang，V.S.(1955)Biochim)分离的类固醇异构酶。生物群落。学报18,300-301)。以5-雄烯-3，17-二酮为底物，酶的亚基相对分子质量为13,750+/-250，等电点为4.8+/-0.1，比活力为40,000个单位/mg。该酶亚基的氨基酸组成为：Lys 2、His 2、Arg 8、Asp 11、Thr 5、Ser4、Glu 17、Pro 8、Gly 12、Ala 12、Val 10、Met 5、Ile 6、Leu 8、Tyr 4、Phe 4和Cys 4。多肽链的这一部分与素β5-3-酮类固醇异构酶的前50个残基的氨基酸序列大约有47%的同源性。恶臭假单胞菌异构酶33~41位氨基酸序列与睾酮假单胞菌异构酶Ala 31~Pro 39区氨基酸序列一致。恶臭巴氏杆菌酶的40个残基是天冬氨酸，在序列上对应于巴氏杆菌睾酮异构酶的天冬氨酸38，已被证明是酶活性所必需的(Ogez，J.R.，Tiol，W.F.和Benisek，W.F.(1977)J.Biol)。化学。252、6151-6155)。
A delta 5-3-ketosteroid isomerase (EC 5.3.3.1) has been isolated from Pseudomonas putida Biotype B and purified to homogeneity. This previously undescribed steroid isomerase resembles that isolated from Pseudomonas testosteroni (Talalay, P., and Wang, V.S. (1955) Biochim. Biophys. Acta 18, 300-301). The enzyme is induced by various steroids, has a subunit molecular weight of 13,750 +/- 250, a pI of 4.8 +/- 0.1 has a specific activity of 40,000 units/mg, using 5-androstene-3,17-dione as the substrate. The amino acid composition of the enzyme subunit is Lys 2, His 2, Arg 8, Asp 11, Thr 5, Ser 4, Glu 17, Pro 8, Gly 12, Ala 12, Val 10, Met 5, Ile 6, Leu 8, Tyr 4, Phe 4, and Cys 4. The amino acid sequence has been determined for the NH2-terminal 50 residues. This portion of the polypeptide chain is approximately 47% homologous with the amino acid sequence of the first 50 residues of the delta 5-3-ketosteroid isomerase from P. testosteroni. The amino acid sequence of residues 33 to 41 of the P. putida isomerase is identical with the region Ala 31 through Pro 39 in the P. testosteroni enzyme. Residue 40 of the P. putida enzyme is aspartic acid and corresponds in the sequence to Asp 38 of the P. testosteroni isomerase, which has been shown to be essential for enzymatic activity (Ogez, J.R., Tivol, W.F., and Benisek, W.F. (1977) J. Biol. Chem. 252, 6151-6155).