MECHANISM OF METHIONINE BIOSYNTHESIS IN RAT LIVER

被引：3

作者：

BURTON, E

SAKAMI, W

机构：

[1] Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio

来源：

EUROPEAN JOURNAL OF BIOCHEMISTRY | 1968年 / 7卷 / 01期

关键词：

D O I：

10.1111/j.1432-1033.1968.tb19565.x

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Synthesis of methionine in rat liver by the B12‐independent N5‐methyltetrahydropterolyltri‐glutamate: homocysteine methyltransferase reported by Wang, Koch and Stokstad has been investigated. In agreement with their results it was found that methionine was formed by crude rat liver supernatant fraction and dialyzed mitochondrial extract on aerobic incubation with N5‐methyltetrahydropteroyltriglutamate, homocysteine and magnesium chloride. However, the folate derivative could not have been involved in this process since N5‐[14C]methyl‐tetrahydropteroyltriglutamate did not incorporate 14C into the methionine. In the supernatant fraction, methionine was formed by the transmethylation of endogenous betaine with added homocysteine. Rat liver supernatant fraction was found to contain 250 nmoles/ml betaine. In the mitochondrial extract, methionine formation occurred by proteolysis. It is concluded that a B12‐independent N5‐methyltetrahydropteroyltriglutamate: homocysteine methyltransferase does not occur in rat liver. Copyright © 1968, Wiley Blackwell. All rights reserved

引用

页码：1 / +

页数：1

共 24 条

[1]

BALDESSARINI ROSS J., 1963, ANALYT BIOCHEM, V6, P289, DOI 10.1016/0003-2697(63)90139-8

[2] PTEROIC ACID DERIVATIVES .3. PTEROYL-GAMMA-GLUTAMYLGLUTAMIC ACID AND PTEROYL-GAMMA-GLUTAMYL-GAMMA-GLUTAMYLGLUTAMIC ACID [J].