Molecular and structural analysis of electrophoretic variants of soybean seed storage proteins.
Soybean (Glycine max L.) storage proteins are composed mainly of two major components, beta-conglycinin and glycinin. Electrophoretic variants of the beta subunit of beta-conglycinin and the A3 polypeptide of glycinin were detected on SDS-PAGE, and designated them as beta* and A3*, respectively. beta* and A3* exhibited higher and lower mobilities, respectively, than the common beta subunit and A3 polypeptide. The N-terminal nine and 10 amino acid sequences of beta* and A3* were completely identical to the previously reported sequences of the beta subunit and the A3 polypeptide, respectively. Analysis using concanavalin A-horseradish peroxidase and treatment with N-glycosidase indicated that glycans were not responsible for the difference in electrophoretic mobility of beta* or A3*. Furthermore, five clones of beta* or beta and three clones of A3*, respectively, were sequenced but we could not detect deletions and insertions except for a single or a few amino acid substitutions as compared with the common beta subunit and A3 polypeptide. These results indicate that a single or a few amino acid substitution affects the electrophoretic mobilities of beta* and A3*.
D000595:Amino Acid Sequence; D052179:Antigens, Plant; D002152:Calorimetry, Differential Scanning; D003001:Cloning, Molecular; D003208:Concanavalin A / Q000737:chemistry; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005916:Globulins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D006023:Glycoproteins / Q000032:analysis; D006026:Glycoside Hydrolases / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000737:chemistry; D006358:Hot Temperature; D008969:Molecular Sequence Data; D020033:Protein Isoforms; D021122:Protein Subunits; D055314:Seed Storage Proteins; D012639:Seeds / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D030262:Soybean Proteins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry* / Q000235:genetics
D052179:Antigens, Plant; D005916:Globulins; D006023:Glycoproteins; D020033:Protein Isoforms; D021122:Protein Subunits; D055314:Seed Storage Proteins; D030262:Soybean Proteins; C013894:beta-conglycinin protein, Glycine max; D003208:Concanavalin A; C011474:glycinin; D006735:Horseradish Peroxidase; D006026:Glycoside Hydrolases