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Nonglycosylated and glycosylated porcine prolactin (PRL) were separated using concanavalin A-Sepharose CL-6B column chromatography and tested for mitogenic and lactogenic activities, as well as immunoaffinity and receptor binding characteristics compared to total (nonseparated) porcine PRL. Mitogenic activity, using Nb2 lymphoma cells, was 4- and 50-fold greater (P less than 0.01) for total PRL than nonglycosylated and glycosylated PRL, respectively. Glycosylated PRL had 64% higher (P less than 0.05) lactogenic activity than nonglycosylated or total PRL. In a homologous radioimmunoassay (RIA), displacement was greatest for total, followed by the nonglycosylated and glycosylated forms of PRL. Competitive inhibition of porcine [125I]-(total) PRL by radioinert total, nonglycosylated and glycosylated PRL in a homologous radioreceptor assay (RRA) indicated similar Ka values for total and nonglycosylated PRL, but different receptor numbers, while radioinert glycosylated PRL had a higher Ka, but bound fewer receptors. Therefore, glycosylated porcine PRL has greater lactogenic activity and higher binding affinity despite decreased mitogenicity, while nonglycosylated PRL had characteristics similar to total PRL. Results from the homologous RRA and the Nb2 assay suggest that both forms of PRL are necessary to achieve biological effects similar to those for total PRL. The two forms of PRL may have individual and collective effects, while changes in the ratio between these forms may influence physiologically diverse effects of PRL on target tissues.
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
September 1988,
The Journal of clinical endocrinology and metabolism,
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
February 1990,
Endocrinology,
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
September 1990,
Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.),
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
August 1986,
International journal of peptide and protein research,
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
September 1988,
Biochemical and biophysical research communications,
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
June 1988,
Endocrinology,
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
May 1993,
Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.),
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
November 1992,
The Journal of clinical endocrinology and metabolism,
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
March 1988,
Biochemical and biophysical research communications,
K H Young, and
W C Buhi, and
N Horseman, and
J Davis, and
R Kraeling, and
D Linzer, and
F W Bazer
January 1996,
Proteins,
