JBC, Vol. 251, Issue 20, 6267-6273, Oct, 1976
Partial purification and characterization of a triglyceride lipase from pig adipose tissue
S. Matsumura, M. Matsuo and Y. Nishizuka
A triglyceride lipase was extracted from defatted pig adipose tissue powder
with dilute ammonia and purified about 230-fold by a combination of
ammonium sulfate fractionation, heparin-Sepharose 4B, DEAE-cellulose, and
Sephadex G-150 column chromatographies and isoelectrofocusing
electrophoresis. The enzyme was distinguishable in physical and kinetic
properties from the two previously defined lipases in adipose tissue,
lipoprotein lipase, and hormone-sensitive lipase. The purified enzyme was
fully active in the absence of serum lipoprotein and was not stimulated by
adenosine 3':5'-monophosphate-dependent protein kinase. In marked contrast
to the already defined lipases, the enzyme was strongly inhibited by serum
albumin. The enzyme had a molecular weigt of about 43,000, a pI of 5.2, and
pH optimum of 7.0. The enzyme hydrolyzed triolein to oleic acid and
glycerol, and did not exhibit esterase activity. The apparent Km for
triolein was 0.05 mM. Physiological roles of this new species of lipase
remained to be explored.