当前位置： SCI文献检索 > JOURNAL OF LIPID RESEARCH期刊下所有文献 > 3-hydroxy-3-methylglutaryl coenzyme A reductase in human liver microsomes: active and inactive forms and cross-reactivity with antibody against rat liver enzyme.

3-hydroxy-3-methylglutaryl coenzyme A reductase in human liver microsomes: active and inactive forms and cross-reactivity with antibody against rat liver enzyme.

Abstract：

:3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the enzyme catalyzing the rate-limiting step in cholesterol biosynthesis, exists in one active (dephosphorylated) and one inactive (phosphorylated) form in liver microsomes obtained from several animal species. The present study was undertaken in order to determine a) whether the human enzyme also exists in active and inactive readily interconvertible forms; b) whether the large inter-individual variation in HMG-CoA reductase activity observed in normal man can be explained by variations in the activation state of the enzyme; and c) to characterize the reactivity of antibodies raised against rat liver HMG-CoA reductase with the intact human microsomal enzyme. HMG-CoA reductase activity, assayed in microsomes prepared in the presence of 50 mM NaF, was only 17 +/- 3% of the activity observed in microsomes prepared from the same liver in the absence of fluoride. Preincubation of microsomes prepared in NaF with alkaline phosphatase resulted in a tenfold increase of enzyme activity, while the activity of microsomes prepared without fluoride was increased also (by about 45%) with this treatment. On the other hand, the activated enzyme could be inactivated by incubation of microsomes with Mg-ATP. In eleven normal weight, normolipidemic gallstone patients, the HMG-CoA reductase activity determined in microsomes prepared without NaF ("standard procedure") reflected well both the "expressed" activity (in microsomes prepared with NaF) and the "total" (fully activated) enzyme activity; correlation coefficients were +0.80 and +0.84, respectively. Preincubation of human liver microsomes with rabbit antiserum against partially purified HMG-CoA reductase from rat liver resulted in a 72 +/- 6% inhibition of enzyme activity.(ABSTRACT TRUNCATED AT 250 WORDS)

journal_name

J Lipid Res

journal_title

Journal of lipid research

authors

Angelin B,Einarsson K,Liljeqvist L,Nilsell K,Heller RA

subject

Has Abstract

pub_date

1984-11-01 00:00:00

pages

1159-66

issue

eissn

0022-2275

issn

1539-7262

journal_volume

pub_type

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3-hydroxy-3-methylglutaryl coenzyme A reductase in human liver microsomes: active and inactive forms and cross-reactivity with antibody against rat liver enzyme.