Tang Jia, Gai Feng
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Biochemistry. 2008 Aug 12;47(32):8250-2. doi: 10.1021/bi801103x. Epub 2008 Jul 18.
When it is bound to lipid bilayers, the conformation and location of the membrane pH (low) insertion peptide (pHLIP) depend on pH. This unique feature allows us to explicitly measure the kinetics leading to different membrane-bound states of pHLIP using a model membrane and stopped-flow technique. Our results show that the membrane association kinetics of pHLIP are multiexponential and are consistent with a parallel membrane interaction mechanism. Interestingly, our results also show that the overall rate at which the membrane-inserted state is formed is almost identical to that of formation of the surface-bound state, while prebinding slows the rate of peptide insertion.
当膜pH（低）插入肽（pHLIP）与脂质双层结合时，其构象和位置取决于pH值。这一独特特性使我们能够使用模型膜和停流技术明确测量导致pHLIP不同膜结合状态的动力学。我们的结果表明，pHLIP的膜结合动力学是多指数的，并且与平行膜相互作用机制一致。有趣的是，我们的结果还表明，形成膜插入状态的总体速率与形成表面结合状态的速率几乎相同，而预结合会减慢肽插入的速率。
