Characterization of B- and C-type low molecular weight glutenin subunits by electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry
Characterization of B- and C-type low molecular weight glutenin subunits by electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry
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DOI：
10.1002/pmic.200401029
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发表时间：
2005-02-01
期刊：
影响因子：
3.4
通讯作者：
Lafiandra, D
中科院分区：
文献类型：
--
作者：
Muccilli, V;Cunsolo, V;Lafiandra, D
低分子量麦谷蛋白亚基 (LMW-GS) 通常根据其分子量和等电点分为三组，即 B-、C- 和 D 组。使用直接与电喷雾电离质谱联用的高效液相色谱 (HPLC) 和与基质辅助激光解吸/电离质谱离线耦合的高效液相色谱 (HPLC) 对从面包小麦品种“中国春”中提取的富集 B 型和 C 型 LMW-GS 组分进行表征，以确定每个组分中存在的组分的数量和相对分子质量，并确定半胱氨酸残基的数量。结合使用这两种技术检查的每个馏分中检测到约 70 种成分，其中 18 种成分是两种馏分共有的。对用 4-乙烯基吡啶烷基化后的级分进行分析，可以确定约 40 个亚基中存在的半胱氨酸的数量。根据相对分子质量和半胱氨酸残基的数量对检测到的蛋白质进行初步分类。 B 和 C 级分均发现交叉污染，并且存在 D 型 LMW-GS。这两个部分还含有意想不到的成分，可能是脂质转移蛋白和欧米伽麦醇溶蛋白。检测到几种分子质量差异较小的共洗脱蛋白表明存在广泛的微观异质性。
Low molecular weight glutenin subunits (LMW-GS) are typically subdivided into three groups, according to their molecular weights and isoelectric points, namely the B-, C-,and D groups. Enriched B- and C-type LMW-GS fractions extracted from the bread wheat cultivar Chinese Spring were characterized using high performance liquid chromatography (HPLC) directly interfaced with electrospray ionization mass spectrometry and HPLC coupled off-line with matrix-assisted laser desorption/ionization mass spectrometry, in order to ascertain the number and relative molecular masses of the components present in each fraction and determine the number of cysteine residues. About 70 components were detected in each of the fractions examined by the combined use of these two techniques, with 18 components common to both fractions. Analysis of the fractions after alkylation with 4-vinylpyridine allowed determination of the number of the cysteines present in about 40 subunits. The proteins detected were tentatively classified based on the relative molecular masses and number of cysteine residues. Cross-contamination was found in both B- and C- fractions, along with the presence of D-type LMW-GS. The two fractions also contained unexpected components, probably lipid transfer proteins and omega-gliadins. The presence of extensive microheterogeneity was suggested by the detection of several co-eluting proteins with minor differences in their molecular masses.