de Kroon A I, McConnell H M
Department of Chemistry, Stanford University, CA 94305.
Proc Natl Acad Sci U S A. 1993 Oct 1;90(19):8797-801. doi: 10.1073/pnas.90.19.8797.
The influence of nonstimulatory "competitor" peptides on the binding of an antigenic peptide to a major histocompatibility complex (MHC) class II molecule was investigated. Using high-performance size-exclusion chromatography and fluorescein-labeled peptides, we show that the presence of the peptides dynorphin A-(1-13) and poly(L-lysine) results in enhancement rather than inhibition of the binding of hen egg lysozyme peptide-(107-116) [HEL-(107-116)] to the detergent-solubilized mouse class II molecule IEd. In parallel, dynorphin A-(1-13) and poly(L-lysine) were found to enhance the specific activation of an IEd-restricted T-cell hybridoma by HEL-(107-116). A molecular mechanism involving an intermediate two peptide-MHC class II protein complex is proposed to explain the enhancement of peptide binding to class II molecules by an irrelevant second peptide.
研究了非刺激性“竞争”肽对抗原肽与主要组织相容性复合体(MHC)II类分子结合的影响。使用高效尺寸排阻色谱法和荧光素标记的肽,我们发现强啡肽A-(1-13)和聚(L-赖氨酸)肽的存在导致溶菌酶肽-(107-116)[HEL-(107-116)]与去污剂溶解的小鼠II类分子IEd的结合增强而非抑制。同时,发现强啡肽A-(1-13)和聚(L-赖氨酸)可增强HEL-(107-116)对IEd限制性T细胞杂交瘤的特异性激活。提出了一种涉及中间双肽-MHC II类蛋白复合物的分子机制,以解释无关的第二种肽增强肽与II类分子结合的现象。