The location of disulphide bonds in monomeric gamma-type gliadins
The location of disulphide bonds in monomeric gamma-type gliadins
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DOI：
10.1006/s0733-5210(97)90100-4
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发表时间：
1997-09-01
影响因子：
3.8
通讯作者：
Wieser, H
中科院分区：
文献类型：
--
作者：
Muller, S;Wieser, H
采用反相高效液相色谱法（RP-HPLC）对Rektor谷蛋白进行分离。两种优势γ型麦胶蛋白（γ 16-和γ 17-麦胶蛋白）经C-8硅胶层析纯化，并在pH 6.0下用热溶酶消化。所得到的胱氨酸肽通过差动高效液相色谱法（在二硫键还原之前和之后的色谱法）进行鉴定。每个蛋白的3个胱氨酸肽通过RP-HPLC分离纯化，还原，用4-乙烯基吡啶烷基化，分析氨基酸序列。γ 16-和γ 17-麦胶蛋白的两个胱氨酸肽由一个二硫键连接的两个片段组成，并且是相同的。其余的胱氨酸肽包含三个由两个二硫键连接的片段，其中一个片段是相同的，而其他片段分别在两个和四个氨基酸残基上不同。结果表明，两种γ型麦胶蛋白的同源半胱氨酸残基通过相同的分子内连锁类型连接。γ -型麦胶蛋白与α -型麦胶蛋白、谷蛋白结合γ -麦胶蛋白和谷蛋白低分子量亚基的分子内二硫键是同源的。二维结构模型表明，二硫键集中在c端相对较小的区域。(C) 1997学术出版社有限公司
Gliadin prepared from gluten of the cultivar Rektor was separated by RP-HPLC on C-18 silica gel. Two dominant gamma-type gliadins (gamma 16- and gamma 17-gliadins) were purified by rechromatography on C-8 silica gel and digested with thermolysin at pH 6.0. Resulting cystine peptides were identified by differential HPLC (chromatography prior to and after reduction of disulphide bonds). Three cystine peptides of each protein were isolated and purified by RP-HPLC, reduced, alkylated with 4-vinylpyridine and analysed for amino acid sequences. Two cystine peptides of each gamma 16- and gamma 17-gliadin consisted of two fragments linked by one disulphide bond and were identical. The remaining cystine peptides contained three fragments linked by two disulphide bonds and were identical in one fragment, whereas the other fragments differed in two and four amino acid residues, respectively. The results demonstrate that homologous cysteine residues of both gamma-type gliadins are connected by the same intramolecular linkage type. Two disulphide bonds occur within the sequence division III and two disulphide bonds between division III and V. The linkage types of gamma-type gliadins are homologous to the intramolecular disulphide bonds of alpha-type gliadins, glutenin-bound gamma-gliadins and low molecular weight (LMW) subunits of glutenin. A two-dimensional structural model indicates that disulphide bonds are concentrated in a relatively small area of the C-terminal domain. (C) 1997 Academic Press Limited.