Phytochemicals are the bioactive components present at micro level in our daily diet, especially the phenolic antioxidants, contribute to the prevention of cardiovascular and other degenerative diseases. Moringa oleifera (MO) leaves polyphenols effect on the activity of 3-hydroxy-3-methylglutaryl Coenzyme A (HMG CoA) reductase was studied using a spectrophotometric assay based on the stoichiome...

The incubation of rat liver microsomal fraction with a serum preparation followed by the re-isolation of the microsomal membranes has resulted in an increase in the concentration of non-esterified cholesterol, a considerable decrease in the activity of 3-hydroxy-3-methylglutaryl-CoA reductase and in an increase in the activity of acyl-CoA-cholesterol acyltransferase in the treated microsomal pr...

3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMG CoA reductase) controls the rate of cholesterol biosynthesis and is itself modulated through feedback suppression by internalized low density lipoprotein (LDL) cholesterol. We measured HMG CoA reductase protein concentration and microsomal enzyme activity in freshly isolated mononuclear leukocytes from normal individuals and patients with het...

An enzyme from Clostridium thermoaceticum has been isolated which reduces disulfides of carbon monoxide dehydrogenase and it has been named CO dehydrogenase disulfide reductase. The enzyme is a tetramer of molecular weight 225,000 made up of four apparently identical monomers. It does not contain methionine or tryptophan and contains 2 calcium and 1 zinc/monomer. NADP or ferredoxin serves as an...

A 3-hydroxypropionate/4-hydroxybutyrate cycle operates in autotrophic CO(2) fixation in various Crenarchaea, as studied in some detail in Metallosphaera sedula. This cycle and the autotrophic 3-hydroxypropionate cycle in Chloroflexus aurantiacus have in common the conversion of acetyl-coenzyme A (CoA) and two bicarbonates via 3-hydroxypropionate to succinyl-CoA. Both cycles require the reductiv...

We describe a method for estimating the total activity of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase (EC 1.1.1.34) in the small intestine of rats. An homogenate of the whole small intestine is prepared rapidly and assayed directly to maximize the yield of enzyme and to minimize opportunity for uncontrolled change in activity. Fresh homogenate inhibits the expression of reductase in hepa...

The Smith-Lemli-Opitz syndrome (SLOS) is a common birth defect-mental retardation syndrome caused by a defect in the enzyme that reduces 7-dehydrocholesterol to cholesterol. Because of this block, patients' plasma cholesterol levels are generally low while 7-dehydrocholesterol concentrations are markedly elevated. In addition, plasma total sterols are abnormally low and correlate negatively wit...

Thirty-Vella-isolated ileal segments in dogs were used to study the regulation of intestinal cholesterol synthesis. This excluded fistula enabled independent in vivo manipulation of luminal and vascular influences on mucosal cells. Segments were studied repeatedly and each animal served as its own control. Cholesterol synthesis rate was assessed by measuring mucosal activity of the rate-limitin...

We have raised two monospecific antibodies against synthetic peptides derived from the membrane domain of the ER glycoprotein 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate limiting enzyme in the cholesterol biosynthetic pathway. This domain, which was proposed to span the ER membrane seven times (Liscum, L., J. Finer-Moore, R. M. Stroud, K. L. Luskey, M. S. Brown, and J. L...