Bieri O, Wirz J, Hellrung B, Schutkowski M, Drewello M, Kiefhaber T
Biozentrum der Universität Basel, Department of Biophysical Chemistry, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.
Proc Natl Acad Sci U S A. 1999 Aug 17;96(17):9597-601. doi: 10.1073/pnas.96.17.9597.
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.
通过测定连接在多肽链特定位置的供体发色团与受体发色团之间的三重态-三重态能量转移速率，可直接测量分子内链扩散。对于供体和受体由甘氨酸和丝氨酸残基的重复单元相连的多肽，在纳秒时间尺度上观察到接触形成的单指数动力学。速率取决于分隔供体和受体的肽键数量（N），对于最短的肽（N = 3），时间常数（τ = 1/k）为20纳秒时速率达到最大值。这为蛋白质折叠过程中第一个侧链接触形成的速度设定了上限。
