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：1978
卷号：75
期号：6
页码：2659-2663
DOI：10.1073/pnas.75.6.2659
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We have studied in detail the binding of fluorescent derivatives of insulin and epidermal growth factor to 3T3 fibroblasts. We have used two types of fluorescent analogues of insulin and epidermal growth factor: highly fluorescent derivatives which have seven to eight rhodamine molecules or fluorescent derivatives which have a single rhodamine molecule per one molecule of insulin or epidermal growth factor. Both types of analogue retained substantial binding affinity as determined by radioreceptor assays and biological activity. The cells labeled with the fluorescent analogues were visualized with a sensitive video intensification microscopic system that enabled us to directly observe the location of the fluorescent hormone on the surface and within the living fibroblasts. We found that both insulin and epidermal growth factor initially bound diffusely to the cell surface and, at 4{degrees
