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：1999
卷号：96
期号：17
页码：9597-9601
DOI：10.1073/pnas.96.17.9597
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A direct measure of intramolecular chain diffusion is obtained by the determination of triplet-triplet energy-transfer rates between a donor and an acceptor chromophore attached at defined points on a polypeptide chain. Single exponential kinetics of contact formation are observed on the nanosecond time scale for polypeptides in which donor and acceptor are linked by repeating units of glycine and serine residues. The rates depend on the number of peptide bonds (N) separating donor and acceptor and show a maximum for the shortest peptides (N = 3) with a time constant ({tau} = 1/k) of 20 ns. This sets an upper limit for the speed of formation of the first side-chain contacts during protein folding.
