Lee J H, Engler J A, Collawn J F, Moore B A
Oral Cancer Research Center, Department of Biochemistry and Molecular, University of Alabama at Birmingham, Birmingham, USA.
Eur J Biochem. 2001 Apr;268(7):2004-12. doi: 10.1046/j.1432-1327.2001.02073.x.
A biopanning process designed to find peptide epitopes specific for cell surface receptors has been used in this study to select seven- and 12-amino-acid peptides capable of binding to and internalizing with the human transferrin receptor (hTfR). Through sequential rounds of negative and positive selection, two peptide sequences were identified that specifically bind to the hTfR. Phage containing the sequences HAIYPRH or THRPPMWSPVWP were inhibited from binding the hTfR in a dose-dependent fashion when peptides of the same sequence were present in a competition assay. Interestingly, transferrin did not compete with either of these sequences for receptor binding, suggesting that these peptides bind a site on the hTfR distinct from the transferrin binding site. When either of these sequences was expressed as a fusion to green fluorescent protein (GFP), the recombinant GFP molecule was internalized in cells expressing the hTfR. These studies suggest that the two peptides can be used to target other proteins into the endosomal pathway. Further, they provide a strategy for identifying peptides that bind to other cell surface receptors that can be used for both diagnostic and therapeutic purposes.
本研究采用一种旨在寻找细胞表面受体特异性肽表位的生物淘选方法，以筛选出能够与人转铁蛋白受体（hTfR）结合并内化的七肽和十二肽。通过连续多轮的阴性和阳性筛选，鉴定出两个能特异性结合hTfR的肽序列。在竞争试验中，当存在相同序列的肽时，含有HAIYPRH或THRPPMWSPVWP序列的噬菌体与hTfR的结合受到剂量依赖性抑制。有趣的是，转铁蛋白并不与这些序列中的任何一个竞争受体结合，这表明这些肽结合在hTfR上与转铁蛋白结合位点不同的位点。当这些序列中的任何一个与绿色荧光蛋白（GFP）融合表达时，重组GFP分子在表达hTfR的细胞中被内化。这些研究表明，这两种肽可用于将其他蛋白靶向到内体途径。此外，它们为鉴定与其他细胞表面受体结合的肽提供了一种策略，这些肽可用于诊断和治疗目的。
