Young K H, Buhi W C, Horseman N, Davis J, Kraeling R, Linzer D, Bazer F W
Department of Animal Science, University of Florida, Gainesville 32611.
Mol Cell Endocrinol. 1990 Jun 18;71(2):155-62. doi: 10.1016/0303-7207(90)90252-4.
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.
使用伴刀豆球蛋白A-琼脂糖CL-6B柱色谱法分离了非糖基化和糖基化的猪催乳素（PRL），并检测了其促有丝分裂和催乳活性，以及与总（未分离）猪PRL相比的免疫亲和力和受体结合特性。使用Nb2淋巴瘤细胞检测促有丝分裂活性，结果显示总PRL的促有丝分裂活性分别比非糖基化和糖基化PRL高4倍和50倍（P<0.01）。糖基化PRL的催乳活性比非糖基化或总PRL高64%（P<0.05）。在同源放射免疫分析（RIA）中，总PRL的取代作用最大，其次是非糖基化和糖基化形式的PRL。在同源放射受体分析（RRA）中，放射性惰性的总PRL、非糖基化PRL和糖基化PRL对猪[125I] -（总）PRL的竞争性抑制表明，总PRL和非糖基化PRL的Ka值相似，但受体数量不同，而放射性惰性的糖基化PRL具有更高的Ka值，但结合的受体较少。因此，糖基化猪PRL尽管促有丝分裂活性降低，但具有更高的催乳活性和结合亲和力，而非糖基化PRL具有与总PRL相似的特性。同源RRA和Nb2分析的结果表明，两种形式的PRL对于实现与总PRL相似的生物学效应都是必需的。两种形式的PRL可能具有个体和共同的作用，而这些形式之间比例的变化可能会影响PRL对靶组织的多种生理效应。
