Structural stability of halophilic proteins.
Structural stability of halophilic proteins.
复制标题
嗜盐蛋白质的结构稳定性。
DOI：
10.1021/bi00526a004
复制
发表时间：
1981
期刊：
影响因子：
2.9
通讯作者：
P. Argos
中科院分区：
文献类型：
--
作者：
J. Rao;P. Argos
对已知的钝顶螺旋藻[2Fe-2S]铁氧还蛋白三级结构中出现的盐杆菌氨基酸交换的检测表明，大多数嗜盐菌的额外酸性残基发生在藻类结构的外表面；然而，铁氧还蛋白活性部位区域没有发生进一步的负变化。对7种亲盐和非亲盐蛋白质的氨基酸组成的统计研究表明，嗜盐分子所使用的氨基酸的体积大大减少，而亲盐和非亲盐分子的总体疏水性基本相同。结果表明，嗜盐蛋白结构稳定的主要方式是通过利用谷氨酸和天冬氨酸的许多外部羧基与胞质盐有效竞争水分。残基体积的减少将防止在高摩尔浓度、反嗜血性KCl存在下的失活。通过避免活性中心表面的额外负电荷，保持了亲盐官能团。
An examination of halobacterial amino acids exchanges as they appear in the known Spirulina platensis [2Fe-2S] ferredoxin tertiary structure indicated that most of the additional acidic residues of the halophiles occurred on the external surface of the alga structure; however, further negative changes were not placed in the ferredoxin active site region. A statistical investigation of the amino acid compositions of seven halophile and nonhalophile protein counterparts indicated that the bulkiness of amino acids used by halophiles is considerably reduced and that the overall hydrophobicity of halophilic and non halophilic molecules was essentially the same. It is suggested that the principal mode of structural stabilization for halophilic proteins is effective competition with the cytoplasmic salt for water through utilization of many external carboxyl groups of glutamic and aspartic acids. A reduction is residue bulkiness would prevent inactivation in the presence of the high molarity, antichaotropic KCl. Halophilic functionality is preserved through avoidance of additional negative charge at the active site surface.