Structural characterization of the dihydropyridine-sensitive calcium channel alpha 2-subunit and the associated delta peptides

Scott D Jay; Alan H Sharp; Steven D Kahl; Thomas S Vedvick; Michael M Harpold; Kevin P Campbell

doi:10.1016/S0021-9258(18)49986-3

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Structural characterization of the dihydropyridine-sensitive calcium channel alpha 2-subunit and the associated delta peptides

Journal article

Open access

Peer reviewed

Structural characterization of the dihydropyridine-sensitive calcium channel alpha 2-subunit and the associated delta peptides

Scott D Jay, Alan H Sharp, Steven D Kahl, Thomas S Vedvick, Michael M Harpold and Kevin P Campbell

The Journal of biological chemistry, Vol.266(5), pp.3287-3293

02/15/1991

DOI: 10.1016/S0021-9258(18)49986-3

PMID: 1847144

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Abstract

Upon disulfide bond reduction, the alpha 2-subunit of the dihydropyridine-sensitive Ca2+ channel undergoes a characteristic mobility shift on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis with the concurrent appearance of the three delta peptides delta 1 (25,000 Da), delta 2 (22,000 Da), and delta 3 (17,000 Da). Densitometric scanning of Coomassie Blue-stained gels shows a stoichiometric ration of 1.0:0.31.47:0.08 for the alpha 2-subunit and the delta peptides 1, 2, and 3, respectively. Characterization of the delta peptides using antibodies, photoincorporation of a hydrophobic probe, and lectin staining shows tham to be antigenically similar hydrophobic glycoproteins. Amino-terminal sequence analysis of the delta peptides reveals three identical sequences that match the predicted amino acid sequence of the alpha 2-subunit starting at Ala935. Enzymatic deglycosylation of the reduced alpha 2.delta complex produces individual core peptides of 105,000 and 17,000 Da, respectively. Treatment of skeletal muscle membranes with high pH in the presence of reducing agents is able to extract the larger amino-terminal peptide but not the smaller carboxyl (delta) peptide, consistent with a single transmembrane domain in the carboxyl (delta) region. The data support a model of the alpha 2-subunit in which the propeptide is processed into two chains that remain attached through disulfide linkages.

Calcium Channels - drug effects

Microsomes - metabolism

Rabbits

Animals

Peptides - metabolism

Electrophoresis, Polyacrylamide Gel

Dihydropyridines - pharmacology

Glycosylation

Muscles - metabolism

Blotting, Western

Hydrogen-Ion Concentration

Details

Title: Subtitle: Structural characterization of the dihydropyridine-sensitive calcium channel alpha 2-subunit and the associated delta peptides
Creators: Scott D Jay - Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City 52242
Alan H Sharp
Steven D Kahl
Thomas S Vedvick
Michael M Harpold
Kevin P Campbell
Resource Type: Journal article
Publication Details: The Journal of biological chemistry, Vol.266(5), pp.3287-3293
DOI: 10.1016/S0021-9258(18)49986-3
PMID: 1847144
NLM abbreviation: J Biol Chem
ISSN: 0021-9258
eISSN: 1083-351X
Publisher: United States
Grant note: HL-39265 / NHLBI NIH HHS HL-14388 / NHLBI NIH HHS
Language: English
Date published: 02/15/1991
Academic Unit: Neurology; Molecular Physiology and Biophysics; Iowa Neuroscience Institute
Record Identifier: 9984068368802771

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