Inhibin alpha-subunit monomer is present in bovine follicular fluid.
The 26 kDa form of the inhibin alpha-subunit monomer was isolated from bovine follicular fluid. Both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analysis revealed that the 26 kDa form of the alpha-subunit monomer is composed of 6 kDa and 20 kDa fragments linked together by a disulfide bond(s). The NH2-terminal sequence and amino acid analyses of each fragment showed that those fragments are derived from residues 18 to 60 and 227 to 360, respectively, of the inhibin alpha-subunit precursor (residues 1 to 360) as deduced from the cDNA sequence. Thus, it is concluded that removal of the putative signal peptide (residues 1 to 17) and the middle portion (residues 61 to 226) from the alpha-subunit precursor generates the 26 kDa form of the alpha-subunit. In the in vitro rat pituitary assay, the 26 kDa alpha-subunit exhibited neither inhibin-like nor FSH-release stimulating activity.
Sugino
K
K
Frontier Research Program, RIKEN, Saitama, Japan.
Nakamura
T
T
Takio
K
K
Titani
K
K
Miyamoto
K
K
Hasegawa
Y
Y
Igarashi
M
M
Sugino
H
H
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007265:Inhibins / Q000302:isolation & purification*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D006080:Ovarian Follicle / Q000032:analysis*; D010446:Peptide Fragments / Q000032:analysis
D000596:Amino Acids; D046911:Macromolecular Substances; D010446:Peptide Fragments; D007265:Inhibins