One- and Two-Dimensional Gel Electrophoresic Identification of African Yam Bean Seed Proteins

• Published in: Journal of agricultural and food chemistry Vol. 48; no. 6; pp. 2296 - 2299
• Main Authors: Machuka, Jesse, Okeola, Oladapo G
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.06.2000
• Subjects: Air. Soil. Water. Waste. Feeding; Amino Acid Sequence; Animals; Biological and medical sciences; Electrophoresis, Gel, Two-Dimensional - methods; Electrophoresis, Polyacrylamide Gel - methods; Environment. Living conditions; Fabaceae - chemistry; Food industries; Food toxicology; Fundamental and applied biological sciences. Psychology; Hemagglutination Tests; Humans; Lectins - analysis; Lectins - chemistry; Lectins - pharmacology; Medical sciences; Molecular Sequence Data; Nutritive Value; Peptide Fragments - chemistry; Plant Lectins; Plant Proteins - analysis; Plant Proteins - chemistry; Plants, Medicinal; Public health. Hygiene; Public health. Hygiene-occupational medicine; Rabbits; Seeds - chemistry; Sequence Alignment; Sequence Homology, Amino Acid; Lectin; Storage protein; pH gradient; Nutrition; Gel electrophoresis; Nutritive value; Hemagglutination test; Identification; Analysis method; Leguminosae; Antimetabolic; Affinity chromatography; Dicotyledones; Antinutrient factor; Angiospermae; N terminal-Sequence; Spermatophyta; Endosperm; Tuber plant; Two dimensional electrophoresis
• DOI: 10.1021/jf990800x
• ISSN: 0021-8561

Seed proteins were extracted from the African yam bean (AYB; Sphenostylis stenocarpa), an underutilized West African food legume. One- and two-dimensional polyacrylamide gel electrophoresis was then used to analyze the albumin fraction, galactose-specific lectins purified on immobilized galactose−Sepharose 4B, and abundant non-lectin seed proteins left over following affinity chromatography. N-terminal sequencing of prominently resolved polypetide bands led to identification of proteins having sequence homology with characterized legume seed proteins, namely, mung bean seed albumin, pea α-fucosidase, soybean Kunitz-type trypsin inhibitor, an endochitinase, pea pathogenesis-related protein, and/or cowpea seed storage proteins. Minor lectin-like proteins lacking hemagglutinating activity against rabbit and human erythrocytes were also identified. Because proteins such as protease inhibitors, chitinases, pathogenesis-related proteins, and lectins are known to have antimetabolic effects, the findings from this study may have relevance in the acceptability, adoption, and utilization of AYB as human food. Keywords: albumins; electrophoresis; lectins; N-terminal protein sequencing; seed proteins; Sphenostylis stenocarpa