Balbach J, Forge V, Lau W S, Jones J A, van Nuland N A, Dobson C M
Oxford Centre for Molecular Sciences, New Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QT, United Kingdom.
Proc Natl Acad Sci U S A. 1997 Jul 8;94(14):7182-5. doi: 10.1073/pnas.94.14.7182.
Protein folding can be described in terms of the development of specific contacts between residues as a highly disordered polypeptide chain converts into the native state. Here we describe an NMR based strategy designed to detect such contacts by observation of nuclear Overhauser effects (NOEs). Experiments with alpha-lactalbumin reveal the existence of extensive NOEs between aromatic and aliphatic protons in the archetypal molten globule formed by this protein at low pH. Analysis of their time development provides direct evidence for near-native compactness of this state. Through a rapid refolding procedure the NOE intensity can be transferred efficiently into the resolved and assigned spectrum of the native state. This demonstrates the viability of using this approach to map out time-averaged interactions between residues in a partially folded protein.
蛋白质折叠可以用残基之间特定接触的发展来描述，即一条高度无序的多肽链转变为天然状态的过程。在这里，我们描述了一种基于核磁共振（NMR）的策略，旨在通过观察核Overhauser效应（NOE）来检测此类接触。对α-乳白蛋白的实验揭示了在低pH条件下由该蛋白质形成的典型熔融球状结构中，芳香族质子和脂肪族质子之间存在广泛的NOE。对它们随时间发展的分析为该状态接近天然的紧密程度提供了直接证据。通过快速重折叠过程，NOE强度可以有效地转移到天然状态的解析和归属谱中。这证明了使用这种方法来描绘部分折叠蛋白质中残基之间时间平均相互作用的可行性。
