PROGRESS WITH LAUE DIFFRACTION STUDIES ON PROTEIN AND VIRUS CRYSTALS
PROGRESS WITH LAUE DIFFRACTION STUDIES ON PROTEIN AND VIRUS CRYSTALS
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DOI：
10.1021/bi00459a001
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发表时间：
1990-02-20
期刊：
影响因子：
2.9
通讯作者：
JOHNSON, LN
中科院分区：
文献类型：
--
作者：
HAJDU, J;JOHNSON, LN
L射线衍射研究对结构分子生物学作出了突出贡献。所得分子图像是测量所需时间内的时间平均值，并对晶体体积内所有分子进行空间平均。直到最近，用传统的X射线源对蛋白质晶体进行测量需要几天或几周的时间。现在，我们有能力获得在晶体反应过程中可能瞬时积累的短寿命结构的原子信息。大分子晶体学的这些新的机遇，以前被认为是一种静态的技术，需要新的发展，启动和监测事件在蛋白质晶体中。几种方法已经证明，蛋白质可以表现出动态性质的晶体，尽管晶格的限制。对催化作用的研究表明，许多酶在晶体中具有活性，其热力学性质与在溶液中显示的相似，但通常具有降低的速率常数[Quiocho &理查兹，1966;由Makinen和Fink（1977）综述]。在晶体中，就像在溶液中一样，蛋白质的每一种结构状态都代表了一个紧密相关的结构子集，这些结构在平均结构周围经历了热波动。精制蛋白质晶体结构的温度因素分析[Artymiuk等人，1979年; Petsko和林格（1984）综述]已经给出了蛋白质分子中原子的迁移率和限制的指示，并且许多配体结合研究已经显示了蛋白质响应晶体中构象变化的能力。一个分子可以采取的结构状态受到晶格力的限制，与晶格不相容的构象变化会破坏晶体。
^ L-ray diffraction studies have made outstandingcontribu-tions to structural molecular biology. The resulting image of the molecule is time averaged over the period needed to make the measurements and spatially averaged over all themolecules within the volume of the crystal. Until recently, the mea-surements from protein crystals took days or weeks with conventional X-ray sources. Now, the ability to obtain atomic information on short-lived structures that may accumulate transiently during a reaction in the crystal is within our grasp. These new opportunities in macromolecular crystallography, which has previously been considered a static technique, re-quire new developements for initiating and monitoring events in protein crystals.Several approaches have demonstrated that proteins can exhibit dynamic properties in the crystaldespite the constraints of the crystal lattice. Studies on catalysis have indicated that many enzymes are active in the crystal with thermodynamic properties similar to those shown in solution but often with reduced rate constants [Quiocho & Richards, 1966; reviewed by Makinen and Fink (1977)]. In the crystal, as in solution, each structural state of a protein represents a subset of closely related structures that undergo thermal fluctuations around the mean structure. Analysis of temperature factors of refined protein crystal structures [Artymiuk et al., 1979; reviewed by Petsko and Ringe (1984)] has given indications of mobility and restraints on atoms in protein molecules, and many ligand binding studies have shown the ability of proteins to respond with conformational changes in the crystal. The structural states that a molecule can adopt are restrained by lattice forces, and conformational changes incompatible with the lattice break up the crystal.