Structural properties of apocytochrome b5: presence of a stable native core.
Structural properties of apocytochrome b5: presence of a stable native core.
复制标题
apocytochrome b5 的结构特性：存在稳定的天然核心。
DOI：
10.1021/bi00460a004
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发表时间：
1990
期刊：
影响因子：
2.9
通讯作者：
Lecomte,JT
中科院分区：
文献类型：
--
作者：
Moore,CD;Lecomte,JT
化学系，宾夕法尼亚州立大学，大学公园，宾夕法尼亚州16802接收1989年11月15日;修订的Mandarin pt接收1989年12月18日摘要：在去除血红素基团后，细胞色素b5的水溶性片段采用比全蛋白更不稳定和紧凑的构象[亨特利，T. E、& Strittmatter，P.（1972）J.Biol.Chem.247，4641-4647]，这种由氨基酸序列单独施加的构象尚未详细描述。应用一维和二维质子核磁共振波谱技术对大鼠肝细胞色素b可溶性片段的载脂蛋白进行了结构表征。核Overhauserspectroscopy揭示了一些短interresidue距离，并表明，尽管增加的灵活性，至少有一个集群的侧链存在的时间尺度上足够长的研究。鉴定了参与簇的几个残基，特别是唯一的Trp（Trp 22）。观察到还原全蛋白光谱的相似性，从而检查细胞色素B}晶体结构以分配共振。看来，该残基的环境在脱辅基蛋白中保持其完整性。由于在全蛋白色氨酸22属于一个疏水性的核心形成的部分由/3-链，有人提出，一些这个/3-结构是稳定的情况下的血红素折叠进行了讨论。
Department of Chemistry, The PennsylvaniaState University, University Park, Pennsylvania 16802 Received November 15, 1989; Revised Manuscript Received December 18, 1989 abstract: Upon removal of the heme group, the water-soluble fragment of cytochrome b5 adopts a conformation less stable and compact than that of the holoprotein [Huntley, T. E., & Strittmatter, P.(1972) J. Biol. Chem. 247, 4641-4647], This conformation, imposed by the amino acid sequence alone, has not been described in detail. One-and two-dimensional proton nuclear magnetic resonance spectroscopy techniques were applied to theapoprotein of the soluble fragment of rat liver cytochrome bs in an effort to characterize the structure of the apoprotein. Nuclear Overhauserspectroscopy revealed a number of short interresidue distances and demonstrated that, in spite of the increased flexibility, at least one cluster of side chains exists on a time scale long enough for study. Several residues participating in the cluster, in particular the only Trp (Trp 22), were identified. Similarities with the spectrum of the reduced holoprotein were observed that led to the inspection of the cytochrome b} crystal structure for assigning resonances. It appeared that the environment of this residue maintains its integrity in the apoprotein. Since in the holoprotein Trp 22 belongs to a hydrophobic core formed in part by/3-strands, it is proposed that some of this/3-structure is stable in the absence of the heme-folding are discussed.