Isolation and molecular characterization of four arginine/glutamate rich polypeptides from the seeds of sponge gourd (Luffa cylindrica).
Four arginine/glutamate rich polypeptides referred to as 5 k-, 6.5 k-, 12.5 k-, and 14 k-AGRPs were purified to homogeneity by gel filtration on Sephadex G-75 followed by CM-cellulose, butyl-Toyopearl 650 M, and reverse-phase HPLC from the seed of sponge gourd (Luffa cylindrica). Tricine SDS-PAGE indicated that 5 k- and 6.5 k-AGRPs are single polypeptides, but 12.5 k- and 14 k-AGRPs consist of two polypeptide chains, which are linked by disulfide bond(s). The N-terminal amino acid sequences of four AGRPs were analyzed by a gas-phase sequencer, and the result indicated that they are distinct molecules. Comparison of the sequences with those of proteins in the protein data base demonstrates that 5 k- and 6.5 k-AGRPs have a significant homology with a basic peptide from pumpkin seeds and with cocoa seed vicilin, respectively, and that 12.5 k- and 14 k-AGRPs are related to 2S seed storage proteins. Furthermore, it was assumed that the four AGRPs might occur in the protein bodies within cells of the seed.
Ishihara
H
H
Laboratory of Protein Chemistry and Engineering, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Sasagawa
T
T
Sakai
R
R
Nishikawa
M
M
Kimura
M
M
Funatsu
G
G
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001120:Arginine / Q000737:chemistry; D005638:Fruit / Q000737:chemistry; D018698:Glutamic Acid / Q000737:chemistry; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
D000596:Amino Acids; D010940:Plant Proteins; D018698:Glutamic Acid; D001120:Arginine