The C-peptide helix from ribonuclease A considered as an autonomous folding unit.
The C-peptide helix from ribonuclease A considered as an autonomous folding unit.
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来自核糖核酸酶 A 的 C 肽螺旋被视为自主折叠单元。
DOI：
10.1101/sqb.1987.052.01.045
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Baldwin,RL
中科院分区：
文献类型：
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作者：
Shoemaker,KR;Fairman,R;Kim,PS;York,EJ;Stewart,JM;Baldwin,RL
研究蛋白质折叠机制的基本目标之一是定义自主折叠单位：蛋白质的那些单独片段，如果被切除，则包含足够的结构信息来指定它们自己的折叠。令人惊讶的是，人们对这个问题知之甚少。一个普遍的观点是，整个域是折叠的单位。结构域被定义为：（1）多肽链的一个连续片段，通过检查蛋白质的X射线结构来判断，它是折叠在自身上的;（2）一个折叠片段，它只与相邻片段边缘接触。通常发现结构域含有100-150个氨基酸残基。蛋白质结构的本质是，一个结构域可以分为两个亚结构域，如果一个亚结构域的定义是基于上述第1部分（Rose 1979），而不是第2部分，那么每个亚结构域可以进一步划分。然而，自主折叠单位可能被证明比整个结构域小得多。吉尔伯特的假说，即新的蛋白质可以通过重组外显子产生（吉尔伯特1978，1985），这意味着每个外显子产物是一个自主折叠单位（参见图11）。G5 1981），外显子编码的肽段通常小至30-40个残基。自主折叠单元的定义与用于折叠结构的稳定性的标准相关联。我们对自主折叠单元的标准如下：（1）切除片段所显示的结构在水溶液中应足够稳定以被检测，并且应通过单分子反应发生。(2)这种结构必须与完整蛋白质的结构非常相似。
One of the basic goals of work on the mechanism of protein folding is to define autonomous folding units: those individual segments of a protein which, if excised, contain sufficient structural information to specify their own folding. Surprisingly little is known about this subject. A common opinion is that entire domains are the units of folding. A domain is defined as (1) a continuous segment of polypeptide chain that is folded on itself, as judged by inspection of the protein's X-ray structure, and (2) a folded segment that makes only marginal contacts with neighboring segments. Domains are usually found to contain 100-150 amino acid residues. The nature of protein structure is such that a domain can be divided into two subdomains and each subdomain can be further divided, if the definition of a subdomain is based on part 1 above (Rose 1979), without part 2.Autonomous folding units might, however, prove to be substantially smaller than entire domains. Gilbert's hypothesis that new proteins can be made by reshuffling exons (Gilbert 1978, 1985) implies that each exon product is an autonomous folding unit (cf. G5 1981) and the peptide segments encoded by exons are often as small as 30-40 residues. The definition of an autonomous folding unit is tied to the criteria used for stability of the folded structure. Our criteria for an autonomous folding unit are as follows:(1) The structure shown by the excised fragment should be sufficiently stable in aqueous solution to be detected, and should occur by a monomolecular reaction.(2) This structure must closely resemble the structure in the intact protein.