Inhibition of phosphorylation of cardiac troponin-I by adenosine and 5'-chloro 5'-deoxyadenosine

Conference · Thu May 01 00:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5022890

Rosenthal, R; Lowenstein, J M

Adenosine inhibits the positive inotropic and chronotropic effects of catecholamines on the heart. Incubation of a crude contractile protein fraction from rat heart with (..gamma..-/sup 32/P)ATP results in the phosphorylation of several proteins by endogenous protein kinases. The adenosine analog 5'-chloro 5'-deoxyadenosine inhibits the phosphorylation of a 29 kDa protein in this preparation. The protein has been identified as cardiac troponin-I (cTn-I) by 2 dimensional gel electrophoresis, with a non-equilibrium pH gradient in the first direction and SDS-PAGE in the second, using purified cTn-I as standard. Addition of catalytic subunit of cAMP-dependent protein kinase to the crude contractile fraction increases phosphorylation of cTn-I; this increase is inhibited by 5'-chloro 5'-deoxyadenosine and adenosine. Phosphorylation of purified cTn-I by the catalytic subunit is also inhibited by 5'-chloro 5'-deoxyadenosine. Fifty percent inhibition of phosphorylation by either endogenous or exogenous kinase was observed at approximately 50 ..mu..M 5'-chloro 5'-deoxyadenosine or adenosine, a concentration within the intracellular range during hypoxia.

• Research Organization: Brandeis Univ., Waltham, MA
• OSTI ID: 5022890
• Report Number(s): CONF-8606151-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ADENOSINE
BIOLOGICAL EFFECTS
PROTEINS
PHOSPHORYLATION
ATP
ELECTROPHORESIS
INHIBITION
PHOSPHORUS 32
PHOSPHOTRANSFERASES
TRACER TECHNIQUES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ENZYMES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
NUCLEI
NUCLEOSIDES
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
RADIOISOTOPES
RIBOSIDES
TRANSFERASES
550201* - Biochemistry- Tracer Techniques