Lysozyme: a model enzyme in protein crystallography.
Lysozyme: a model enzyme in protein crystallography.
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溶菌酶：蛋白质晶体学中的模型酶。
DOI：
10.1007/978-3-0348-9225-4_11
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发表时间：
1996
影响因子：
4.7
通讯作者：
James Mn
中科院分区：
文献类型：
--
作者：
Strynadka Nc;James Mn
本文主要综述了几个蛋白质晶体学实验室对三种不同溶菌酶的晶体结构研究结果，即c型溶菌酶如蛋清溶菌酶（HEWL）， g型溶菌酶如鹅蛋清溶菌酶（GEWL）和T4噬菌体溶菌酶（T4L）。对几种不同晶体形式的HEWL的晶体学研究表明，溶菌酶分子相对刚性，活性位点Glu35和Asp52的残基在所有结构和物种变体中几乎采用相同的构象。核磁共振结果也证实了溶液中存在类似的HEWL构象。这三种酶，hehl， GEWL和T4L都由两个结构域组成，一个主要是α -螺旋结构域，另一个较小的结构域主要是β -片。每个溶菌酶的一般酸/一般碱残基（HEWL中的Glu35， GEWL中的Glu73和T4L中的Glu11）由较大的α -螺旋结构域贡献。HEWL和T4L的β -sheet结构域在各自的活性位点上贡献了天冬氨酸，这可能与低聚糖水解途径上D位糖的氧羰基离子中间体的静电稳定有关。在GEWL中没有类似的天冬氨酸羧酸基团，尽管微小的构象变化可以使Asp86或Asp97中的一个或另一个发挥这种稳定作用。底物类似物、过渡态模拟物和水解低聚糖产物与hel、GEWL和T4L的结合极大地促进了我们对糖与蛋白质结合的理解。观察到的这些酶的自由形式与结合形式的细微构象差异最好通过抑制剂存在时活性位点间隙的缩小来描述。本文介绍并讨论了三种酶HEWL、GEWL和T4L的寡糖结合间隙上的残基与位点A、B、C和D上的糖残基的结合相互作用的细节。（GlcNAc）n的低聚糖和交替的MurNAc-GlcNAc-MurNAc结合在这三种酶上，并在高分辨率下测定了结构。这些结合的研究对我们理解溶菌酶糖苷酶活性的催化机制有很大的帮助。本文介绍并讨论了目前公认的有关这一机制的观点。
The review concentrates on the crystal structure results from several protein crystallography laboratories on three different lysozymes, the type-c lysozymes such as hen egg-white lysozyme (HEWL), the type-g lysozyme, such as goose egg-white lysozyme (GEWL), and the lysozyme from T4 bacteriophage (T4L). The crystallographic studies on HEWL in several different crystal forms have shown that the lysozyme molecule is relatively rigid with the residues of the active site Glu35 and Asp52 adopting almost identical conformations in all structures and species variants. The NMR results also confirm the presence of a similar conformation of HEWL in solution. All three enzymes, HEWL, GEWL and T4L are composed of two domains, one that is predominantly alpha-helical and a smaller domain that is mainly beta-sheet in nature. The general acid/general base residue in each lysozyme (Glu35 in HEWL, Glu73 in GEWL and Glu11 in T4L) is contributed by the larger alpha-helical domain. The beta-sheet domains of HEWL and T4L contribute an aspartate to their respective active sites, which is likely involved in electrostatic stabilization of the oxycarbonium ion intermediate of the site D sugar on the hydrolytic pathway of oligosaccharides. There is no analogous aspartate carboxylate group in GEWL although minor conformational changes could position one or other of Asp86 or Asp97 for such a stabilization role. The binding of substrate analogues, transition state mimics and oligosaccharide products of hydrolysis to HEWL, GEWL and T4L have contributed greatly to our understanding of sugar binding to proteins. The observed subtle conformational differences of the free vs bound forms of these enzymes are best described by a narrowing of the active site clefts in the presence of the inhibitors. Details of the binding interactions of those residues lining the oligosaccharide binding clefts of the three-enzymes HEWL, GEWL and T4L with the sugar residues in sites A, B, C and D are presented and discussed. Oligosaccharides of (GlcNAc)n and alternating MurNAc-GlcNAc-MurNAc have been bound to these three enzymes and the structures determined at high resolution. These binding studies have contributed greatly to our understanding of the catalytic mechanism of the lysozyme glycosidase activity. The currently accepted view of this mechanism is presented and discussed in this review.
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影响因子：
2.9
作者：
RYPNIEWSKI, WR;HOLDEN, HM;RAYMENT, I
通讯作者：
RAYMENT, I
影响因子：
5.6
作者：
WEAVER, LH;MATTHEWS, BW
通讯作者：
MATTHEWS, BW
泛素依赖性降解底物的晶体结构：溶菌酶的三二硫键形式。
DOI：
10.1073/pnas.90.9.4136
发表时间：
1993
影响因子：
11.1
作者：
Hill,CP;Johnston,NL;Cohen,RE
通讯作者：
Cohen,RE
影响因子：
2.9
作者：
HARDY, LW;POTEETE, AR
通讯作者：
POTEETE, AR
三斜溶菌酶的精制：II．
DOI：
10.1107/s0108768189009195
发表时间：
1990
期刊：
Acta crystallographica. Section B, Structural science
影响因子：
--
作者：
Ramanadham,M;Sieker,LC;Jensen,LH
通讯作者：
Jensen,LH