CONVERSION OF CHOLESTEROL TO BILE ACIDS IN RAT - PURIFICATION AND PROPERTIES OF A DELTA4-3-KETOSTEROID 5BETA-REDUCTASE AND A 3ALPHA-HYDROXYSTEROID DEHYDROGENASE - BILE ACIDS AND STEROIDS 187
CONVERSION OF CHOLESTEROL TO BILE ACIDS IN RAT - PURIFICATION AND PROPERTIES OF A DELTA4-3-KETOSTEROID 5BETA-REDUCTASE AND A 3ALPHA-HYDROXYSTEROID DEHYDROGENASE - BILE ACIDS AND STEROIDS 187
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DOI：
10.1111/j.1432-1033.1967.tb00163.x
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发表时间：
1967-01-01
期刊：
影响因子：
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通讯作者：
BERSEUS, O
中科院分区：
文献类型：
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作者：
BERSEUS, O
一种对7 α-羟基胆甾-4-烯-3-酮和7 α，12 α-二羟基胆甾-4-烯-3-酮有活性的δ-4 -3-酮甾族化合物5 δ-还原酶和对7 α-羟基-5 β-胆甾烷-3-酮和7 α有活性的3 α-羟基甾族化合物脱氢酶，12[α]-二羟基-5 [β]-胆甾烷-3-酮从大鼠肝匀浆的可溶性部分中分离，并通过TEAE -纤维素和Sephadex G-75色谱法部分纯化。[DELTA]4-3-酮类甾体5[bata]-还原酶需要NADPH作为辅因子，并被对氯汞苯甲酸可逆地抑制。该酶制剂催化C19、C21、C24和C27系列的许多[DELTA]4 - 3-酮甾族化合物中双键的还原。在[Δ]4-3-酮甾5[β]-还原酶制剂的存在下，7[α]，12[α]-二羟基胆甾-4-烯-3-酮的还原不受加入7[α]-羟基胆甾-4-烯-3-酮的抑制，7[α]-羟基胆甾-4-烯-3-酮的还原不受7[α]，12[α]-二羟基胆甾-4-烯-3-酮，表明这些底物被[DELTA]4-3-酮甾族化合物5 B-还原酶制剂中存在的不同还原酶还原。3[alpha]-羟基类固醇脱氢酶需要还原的吡啶核苷酸，优选NADPH，并被对氯汞苯甲酸可逆地抑制。该酶制剂催化C19、C21、C24和C27系列的许多3-酮甾族化合物中的3-酮基的还原。3-酮-5 [β]-类固醇的降低速率快于相应的3-酮-5 [α]-类固醇。
A [DELTA]4-3-ketosteroid 5[DELTA]-reductase active on 7a-hydroxycholest-4-en-3-one and 7[alpha],12[alpha]-dihydroxycholest-4-en-3-one and a 3[alpha]-hydroxy steroid dehydrogenase active on 7[alpha]-hydroxy-5[beta]-cholestan-3-one and 7[alpha],12[alpha]-dihydroxy-5[beta]-cholestan-3-one was isolated from the soluble fraction of a rat liver homogenate and was partially purified by chromatography on TEAE -cellulose and Sephadex G-75. The [DELTA]4-3-ketosteroid 5[bata]-reductase required NADPH as cofactor and was inhibited reversibly by p-chloromercuribenzoate. The enzyme preparation catalyzed the reduction of the double bond in a number of [DELTA]4 -3-ketosteroids of the C19, C21, C24, and C27 series. The reduction of 7[alpha], 12[alpha]-dihydroxycholest-4-en-3-one on the presence of the[DELTA]4-3-ketosteroid 5[beta]-reductase preparation was not inhibited by addition of 7[alpha]-hydroxycholest-4-en-3-one and the reduction of 7[alpha]-hydroxycholest-4-en-3-one was not inhibited by 7[alpha],12[alpha]-dihydroxycholest-4-en-3-one indicating that these substrates were reduced by different reductases present in the [DELTA]4-3-ketosteroid 5B-reductase preparation. The 3[alpha]-hydroxysteroid dehydrogenase required reduced pyridine nucleotide, NADPH being preferred, and was inhibited reversibly by p-chloromercuribenzoate. The enzyme preparation catalyzed the reduction of the 3-keto group in a number of 3-ketosteroids of the C19, C21, C24, and C27 series. The rate of reduction was faster with 3-keto-5[beta]-steroids than with the corresponding 3-keto-5[alpha]-steroids.