Tumor promoter 12-O-tetradecanoyl phorbol 13-acetate and regulatory diacylglycerols are substrates for the same carboxylesterase

Journal Article · Sun Jun 15 04:00:00 EDT 1986 · J. Biol. Chem.; (United States)

OSTI ID:5234371

Mentlein, R

Rat liver homogenate or cell fractions deacylate 12-O-tetradecanoyl phorbol 13-acetate (TPA) in vitro mainly by conversion to phorbol 13-acetate. The highest specific activity is located in the microsomal fraction. The deacylation is inhibited by bis-(4-nitrophenyl) phosphate, a selective inhibitor of nonspecific carboxylesterases. Only two of five purified esterases from rat liver endoplasmic reticulum deacylate TPA. These two esterases have formerly been characterized as acylcarnitine hydrolases and the more active one is also a potent diacylglycerol lipase. Its TPA-hydrolyzing activity is inhibited by other substrates like 1-naphthylacetate, lauroylcarnitine, or dioleoyl glycerol. The results support the view that phorbol esters act like structural analogs of diacylglycerols, not only with respect to their activating effect on protein kinase C, but also as substrates for the same lipases.

• Research Organization: Universitaet Kiel, Germany, F.R.
• OSTI ID: 5234371
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 17; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALCOHOLS
ANIMALS
BIOCHEMICAL REACTION KINETICS
BODY
CARBOXYLESTERASES
CARCINOGENS
DIGESTIVE SYSTEM
ENZYMES
ESTERASES
ESTERS
GLANDS
GLYCEROL
HYDROLASES
HYDROXY COMPOUNDS
KINETICS
LABELLED COMPOUNDS
LIPASE
LIVER
MAMMALS
ORGANIC COMPOUNDS
ORGANS
PHORBOL ESTERS
PROMOTERS
RATS
REACTION KINETICS
RODENTS
SUBSTRATES
TRITIUM COMPOUNDS
TUMOR PROMOTERS
VERTEBRATES