Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry Analysis of Zeins in Mature Maize Kernels
详细信息 查看全文
- 作者：Whitney R. Adams ; Shihshieh Huang ; Alan L. Kriz ; and Michael H. Luethy
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2004
- 出版时间：April 7, 2004
- 年：2004
- 卷：52
- 期：7
- 页码：1842 - 1849
- 全文大小：212K
- 年卷期：v.52,no.7(April 7, 2004)
- ISSN：1520-5118
文摘
A high-throughput method has been developed to allow rapid analysis of maize seed storage proteinsby matrix-assisted laser desorption time-of-flight mass spectrometry. The extraction solution containingan organic solvent, a reducing agent, and a volatile base has been optimized to enable extraction ofall classes of zein proteins (
-, 
-, 
-, and 
-). A near-saturating concentration of matrix,2-(4-hydroxyphenylazo)benzoic acid, was necessary to obtain strong peaks for the most lipophiliczeins, the -zeins. Zein proteins with small mass differences, difficult to separate by sodium dodecylsulfate polyacrylamide gel electrophoresis, were resolved through this analysis. Mass signalscorresponding to the 10-kDa -, 15-kDa -, 16-kDa -, 27-kDa -, and several 19 and 22-kDa -zeinswere detected. The zein identities were further confirmed by the association of the number of cysteineresidues in each zein MS peak, as determined by iodoacetamide derivatization, with the numberpredicted from its coding sequence. The relative zein abundance in the zein MS peaks was alsocorrelated with the relative zein EST abundance among endosperm EST libraries. This method wasutilized to examine the zein composition of a number of corn inbred lines and opaque mutants.Keywords: MALDI-TOF MS; zeins; prolamins; maize kernels
-, -, -, and -). A near-saturating concentration of matrix,2-(4-hydroxyphenylazo)benzoic acid, was necessary to obtain strong peaks for the most lipophiliczeins, the -zeins. Zein proteins with small mass differences, difficult to separate by sodium dodecylsulfate polyacrylamide gel electrophoresis, were resolved through this analysis. Mass signalscorresponding to the 10-kDa -, 15-kDa -, 16-kDa -, 27-kDa -, and several 19 and 22-kDa -zeinswere detected. The zein identities were further confirmed by the association of the number of cysteineresidues in each zein MS peak, as determined by iodoacetamide derivatization, with the numberpredicted from its coding sequence. The relative zein abundance in the zein MS peaks was alsocorrelated with the relative zein EST abundance among endosperm EST libraries. This method wasutilized to examine the zein composition of a number of corn inbred lines and opaque mutants.Keywords: MALDI-TOF MS; zeins; prolamins; maize kernels