Purification and characterization of pituitary bovine somatotropin.
Bovine somatotropin (bST) has been isolated from pituitary glands and compared in a variety of chemical analyses and bioassays with somatotropin derived from recombinant Escherichia coli. Comparison of pituitary extracts and purified bST by Western blot analysis of two-dimensional gels suggested that the immunoreactive somatotropin species present in the extract were also present in the purified material, with no significant losses or degradation as a result of the purification method. NH2-terminal sequence analysis indicated the presence of equal quantities of Ala-Phe-Pro-Ala-Met-Ser-Leu-Ser- and Phe-Pro-Ala-Met-Ser-Leu-Ser- sequences. The Met-Ser-Leu-Ser-NH2-terminal sequence, a degradation product observed in NIH standard lots, was not detected. Assay of bioactivity in a bovine liver receptor-binding assay and in a female rat growth assay showed pituitary bST and recombinant methionyl-bovine somatotropin to be equipotent. Tryptic maps and sequence analysis of pituitary-derived somatotropin suggest the presence of isoaspartate derivatization at Asp128.
Wood
D C
DC
Monsanto Company, Saint Louis, Missouri 63198.
Salsgiver
W J
WJ
Kasser
T R
TR
Lange
G W
GW
Rowold
E
E
Violand
B N
BN
Johnson
A
A
Leimgruber
R M
RM
Parr
G R
GR
Siegel
N R
NR
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D013006:Growth Hormone / Q000302:isolation & purification* / Q000378:metabolism; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D010902:Pituitary Gland / Q000032:analysis*; D010907:Pituitary Hormones / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats
D010907:Pituitary Hormones; D013006:Growth Hormone