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

Journal Article · Sun Jun 15 00:00:00 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), Vol. 17
• Country of Publication: United States
• Language: English

Related Subjects

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