Linked Life Data

8095409

Source:http://linkedlifedata.com/resource/pubmed/id/8095409

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1993-4-13
pubmed:abstractText
(S)-(3-Hydroxy-3-methyl-1-thionoglutaryl)-Coenzyme A (HMG[= S]CoA), a dithioester analog of (S)-(3-hydroxy-3-methylglutaryl)-CoA (HMG-CoA), acts as an efficient alternative substrate for avian HMG-CoA lyase. Detection of product formation by HPLC, UV absorbance and coupled enzyme assays indicates that HMG[= S]CoA cleavage yields acetyl[= S]CoA and acetoacetate. HMG[= S]CoA binds to the lyase with a Km of 13 microM and undergoes the cleavage reaction at a maximal rate which is 20% of that observed with HMG-CoA. The enzyme-catalyzed cleavage of both HMG-CoA and HMG[= S]CoA is stimulated by the divalent cations Mg2+ and Mn2+. Mg2+ produces a 2-fold higher stimulation of HMG-CoA cleavage than that observed with Mn2+. In contrast, stimulation of HMG[= S]CoA cleavage is nearly seven times higher with Mn2+ than with Mg2+. Not only is the stimulation of enzymatic activity dependent on the cation, but also the Km values for Mg2+ and Mn2+ are dependent upon the substrate used. In contrast, the Km values for HMG-CoA and HMG[= S]CoA are not markedly dependent on the identity of the divalent cation. These results are compatible with the initial formation of a binary enzyme-substrate complex prior to binding of the divalent cation to produce a catalytically active enzyme-substrate-metal ternary complex.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
1162
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
149-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
3-Hydroxy-3-methylglutaryldithio-CoA: utility of an alternative substrate in elucidation of a role for HMG-CoA lyase's cation activator.
pubmed:affiliation
Department of Biochemistry, Medical College of Wisconsin, Milwaukee 53226.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't