Journal of Lipid Research, Vol 23, 257-265, Copyright © 1982 by Lipid Research, Inc.
Recovery and activation of hydroxymethylglutaryl coenzyme A reductase from rat small intestine
NL Young, CD Saudek, SA Crawford and SL Zuckerbrod
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 hepatic microsomes, has high HMG-CoA
cleavage activity, and forms NADPH-independent metabolites which
contaminate mevalonolactone isolated by thin-layer chromatography. When
homogenate is preincubated, these interfering factors are decreased and
reductase activity is increased. Part of this increase can be inhibited by
F-. After freezing and preincubation, total reductase activity recovered
from homogenates of small intestine from 300-g male rats at the middle of
their dark period is 40 nmol mevalonate per min compared to 70 from hepatic
microsomes. If F- is added at the time of homogenization, an activity of 11
nmol per min is recovered from each organ. Reductase in intestinal
homogenate has an apparent Km for S-HMG-CoA of 4 microM.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
