Direct interaction between the catalytic subunit of the calmodulin-sensitive adenylate cyclase from bovine brain with /sup 125/I-labeled wheat germ agglutinin and /sup 125/I-labeled calmodulin

Journal Article · Tue Jul 14 00:00:00 EDT 1987 · Biochemistry; (United States)

OSTI ID:6070582

Minocherhomjee, A M; Selfe, S; Flowers, N J; Storm, D R

A calmodulin-sensitive adenylate cyclase has been purified to apparent homogeneity from bovine cerebral cortex using calmodulin-Sepharose followed by forskolin-Sepharose and wheat germ agglutinin-Sepharose. The final product appeared as one major polypeptide of approximately 135,000 daltons on sodium dodecyl sulfate-polyacrylamide gels. This polypeptide was a major component of the protein purified through calmodulin-Sepharose. The catalytic subunit was stimulated 3-4-fold by calmodulin (CaM) with a turnover number greater than 1000 min/sup -1/ and was directly inhibited by adenosine. The catalytic subunit of the enzyme interacted directly with /sup 125/I-CaM on a sodium dodecyl sulfate-polyacrylamide gel overlay system, and this interaction was Ca/sup 2 +/ concentration dependent. In addition, the catalytic subunit was shown to directly bind /sup 125/I-labeled wheat germ agglutinin using a sodium dodecyl sulfate-polyacrylamide gel overlay technique, and N-acetylglucosamine inhibited binding of the lectin to the catalytic subunit. Calmodulin did not inhibit binding of wheat germ agglutinin to the catalytic subunit, and the binding of calmodulin was unaffected by wheat germ agglutinin. These data illustrate that the catalytic subunit of the calmodulin-sensitive adenylate cyclase is a glycoprotein which interacts directly with calmodulin and that adenosine can inhibit the enzyme without intervening receptors or G coupling proteins. It is concluded that the catalytic subunit of adenylate cyclase is a transmembrane protein with a domain accessible from the outer surface of the cell.

• Research Organization: Univ. of Washington, Seattle
• OSTI ID: 6070582
• Journal Information: Biochemistry; (United States), Vol. 26:14
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
AGGLUTININS
CONFIGURATION INTERACTION
CYCLASES
AUTORADIOGRAPHY
MOLECULAR STRUCTURE
ATP
BRAIN
CATTLE
DOSE-RESPONSE RELATIONSHIPS
ELECTROPHORESIS
GLUCOPROTEINS
IODINE 125
PHOSPHORUS 31
TRITIUM COMPOUNDS
ANIMALS
ANTIBODIES
BETA DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LYASES
MAMMALS
NERVOUS SYSTEM
NUCLEI
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHOSPHORUS ISOTOPES
PROTEINS
RADIOISOTOPES
RUMINANTS
SACCHARIDES
STABLE ISOTOPES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics