DISTRIBUTION OF END-TO-END DISTANCES OF OLIGOPEPTIDES IN SOLUTION AS ESTIMATED BY ENERGY-TRANSFER
DISTRIBUTION OF END-TO-END DISTANCES OF OLIGOPEPTIDES IN SOLUTION AS ESTIMATED BY ENERGY-TRANSFER
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DOI：
10.1073/pnas.72.5.1807
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发表时间：
1975-01-01
影响因子：
11.1
通讯作者：
STEINBERG, IZ
中科院分区：
文献类型：
--
作者：
HAAS, E;WILCHEK, M;STEINBERG, IZ
采用固相法合成了末端分别含有电子激发能供体和受体的同源寡肽系列。N-5-（2-羟乙基）- l -谷氨酰胺为重复单元，制备了含有4、5、6、7、8和9个氨基酸残基的肽。根据Förster机制，分别作为供体和受体的发色团萘和丹酚满足能量转移的必要条件。计算了50%能量传递效率对应的距离，tro = 22±1a。仅含萘发色团的低聚物的荧光衰减动力学可以用单指数函数精确描述。相比之下，所有含有供体和受体的低聚物的供体荧光衰减曲线的动力学，在粘性溶液中测量，明显偏离单指数行为。这种偏差被解释为每种低聚物的不同分子在溶液中获得的大量不同构象，导致供体和受体之间的特征端到端分布函数。对先前提出的一些描述端到端分布的表达式的参数进行数值调整，可以非常精确地重建供体的荧光衰减动力学。因此，评估了各种寡肽的端到端分布函数。
A homologous series of oligopeptides each containing at its ends a donor and an acceptor of electronic excitation energy was synthesized by the solid-phase method. N-5-(2-Hydroxyethyl)-L-glutamine was the repeating unit, and peptides containing 4, 5, 6, 7, 8, and 9 of these amino-acid residues were prepared. The chromophores naphthalene and dansyl, which were used as donor and acceptor, respectively, fulfil the conditions necessary for energy transfer according to the Förster mechanism. A distance corresponding to 50% efficiency of energy transfer, tro = 22 plus or minus 1 A, was calculated. The kinetics of fluorescence decay of an oligomer containing the naphthalene chromophore only could be described precisely by a monoexponential function. In contrast, the kinetics of the decay curves of the fluorescence of the donor of all of the oligomers containing both donor and acceptor, as measured in viscous solution, deviated markedly from monoexponential behavior. The deviation was interpreted in terms of the great number of different conformations that the various molecules of each of the oligomers attain in solution, leading to characteristic end-to-end distribution functions between the donor and acceptor. Numerical adjustment of the parameters of some of the previously proposed expressions to describe the end-to-end distribution enabled the reconstruction of the kinetics of the fluorescence decay of the donor with great precision. The end-to-end distribution functions for the various oligopeptides were thus evaluated.