Abstract
Rice glutelin, which accounts for 70–80% of the total proteins of the seeds, consists of two nutritionally different subfamilies (A and B types). Although the similarity in primary sequences between the two subfamilies is as high as 60%, we established conditions to discriminate the two subfamilies when low amounts of antigen are analyzed by immunoblot methods. The glutelin α polypeptides can be resolved into six bands labeled α1 to α6 by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Gel filtration analysis showed that glutelin exists as a polymerized and a smaller molecular weight form. Immunoblot analysis of SDS-PAGE resolved polypeptides showed that α2, α3, and α4 are an A type and that these A types as well as α1, a B type, are polymerized. The polymerization tendency clearly differed between the two subfamilies except for α1, which may be derived from GluB-4 as suggested by analysis using Escherichia coli expression systems of glutelin cDNA regions corresponding to α polypeptides. GluB-4 and all the A type subunits have an extra Cys residue in the hypervariable regions, corresponding to the C-terminal region of α polypeptide. Accordingly, the extra Cys residue is hypothesized to be responsible for the polymerization of glutelin.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Biochimica et Biophysica Acta (BBA) - Proteins & Proteomics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.