Send to:

Choose Destination
See comment in PubMed Commons below
Biochem J. 1985 Apr 15;227(2):591-9.

3-Hydroxy-3-methylglutaryl-coenzyme A synthase from ox liver. Purification, molecular and catalytic properties.


Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (EC was purified to homogeneity from ox liver and obtained essentially free from acetoacetyl-CoA thiolase activity. The purification procedure included substrate elution from cellulose phosphate and chromatofocusing. The relative molecular mas was about 100 000 and S20,w0 was 6.36S. The enzyme appears to be a dimer of identical subunits (Mr 47 900). The Km for acetoacetyl-CoA is extremely low (less than 0.5 microM), and acetoacetyl-CoA (Acac-CoA) gives marked substrate inhibition (KiAcac-CoA = 3.5 microM) that is competitive with respect to acetyl-CoA. Both CoA and DL-3-hydroxy-3-methylglutaryl-CoA give mixed product inhibition with respect to acetyl-CoA, which is compatible with a Ping Pong mechanism in which both products can form kinetically significant complexes with two forms of the enzyme. The two forms are most likely to be free enzyme and an acetyl-enzyme intermediate.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk