期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1981
卷号：78
期号：6
页码：3973-3975
DOI：10.1073/pnas.78.6.3973
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The binding of salmon calcitonin was investigated in subcellular fractions obtained from normal porcine lung. Only the membrane fraction (density, 1.14 g/cm3) showed specific binding for calcitonin. Specific binding of 125I-labeled salmon calcitonin was competitively inhibited by concentrations of unlabeled homologous hormone in the range 0.01-1 nM. Half-maximal inhibition of binding was observed with 0.12 nM salmon calcitonin. Scatchard analysis of the data suggested the presence of one class of binding sites with a mean affinity constant of 0.9 X 10(10) M-1 and a mean receptor number of 40 X 10(8)/mg of protein. The binding of salmon calcitonin was highly specific; half-maximal inhibition of binding was observed with 63.8 nM bovine calcitonin, the hormone corticotropin having no effect in this system.
