TY - JOUR
T1 - Distribution of calmodulin and calmodulin‐binding proteins in membranes from bovine epididymal spermatozoa
AU - Noland, Thomas D.
AU - Van Eldik, Linda J.
AU - Garbers, David L.
AU - Burgess, Wilson H.
PY - 1985
Y1 - 1985
N2 - Reproducible concentrations of calmodulin representing approximately 0.1% of the membrane protein were detected in purified plasma membranes from bovine epididymal spermatozoa. When membranes were isolated in the presence of 1 mM EGTA, the amount of calmodulin associated with the plasma membranes was not reduced. Calmodulin‐binding proteins were detected in both purified plasma membranes and in a mixed membrane fraction containing both plasma membranes and cytoplasmic droplet membranes. A calcium‐dependent, calmodulin‐binding protein of apparent molecular weight 123,000 was detected in both fractions. In the presence of 1 mM EDTA, putative calcium‐independent calmodulin‐binding proteins of apparent molecular weights 93,000, 32,000, 18,000, and 15,000 were detected in the plasma membrane fraction. The 15,000 Mr polypeptide was also present in the mixed membrane fraction but the three proteins of higher molecular weight were reduced or absent in this fraction.
AB - Reproducible concentrations of calmodulin representing approximately 0.1% of the membrane protein were detected in purified plasma membranes from bovine epididymal spermatozoa. When membranes were isolated in the presence of 1 mM EGTA, the amount of calmodulin associated with the plasma membranes was not reduced. Calmodulin‐binding proteins were detected in both purified plasma membranes and in a mixed membrane fraction containing both plasma membranes and cytoplasmic droplet membranes. A calcium‐dependent, calmodulin‐binding protein of apparent molecular weight 123,000 was detected in both fractions. In the presence of 1 mM EDTA, putative calcium‐independent calmodulin‐binding proteins of apparent molecular weights 93,000, 32,000, 18,000, and 15,000 were detected in the plasma membrane fraction. The 15,000 Mr polypeptide was also present in the mixed membrane fraction but the three proteins of higher molecular weight were reduced or absent in this fraction.
KW - calcium‐modulated proteins
KW - calmodulin
KW - calmodulin‐binding proteins
KW - membranes
KW - spermatozoa
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U2 - 10.1002/mrd.1120110309
DO - 10.1002/mrd.1120110309
M3 - Article
AN - SCOPUS:0021998123
SN - 0148-7280
VL - 11
SP - 297
EP - 303
JO - Gamete Research
JF - Gamete Research
IS - 3
ER -