The complete amino acid sequence and disulphide bond arrangement of oat alcohol-soluble avenin-3.
We have elucidated the complete amino acid sequence of one of the avenin components, avenin-3, isolated from oat (Avena sativa L.), variety Narymsky 943. The sequence of the protein was determined by sequencing of CNBr and trypsin-generated peptides in combination with mass spectrometry. The protein is a single polypeptide chain, consisting of 201 amino acid residues with M(r) 23,252.8. The N-terminal amino acid residue of the protein is blocked with 5-oxoproline (pyroglutamic acid). All eight cysteine residues in avenin-3 are involved in disulphide bonds. The positions of these bonds were established by identification of a CNBr cleavage product of the intact avenin containing all the disulfide bonds (S-S core). Subsequent subdigestion of this S-S core allowed isolation of disulphide bonded peptides detected by differential reverse-phase HPLC before and after reduction. As a result, all four disulphides Cys50 Cys183, Cys58 Cys77, Cys84 Cys85 and Cys97 Cys191 were identified. Comparison of avenins with other prolamins demonstrates a high degree of similarity, which is especially pronounced around the cysteine residues. Avenins differ slightly from other prolamins in having unique N-terminal sequences and some differences in the repeated sequence motifs.
Egorov
T A
TA
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow.
Musolyamov
A K
AK
Andersen
J S
JS
Roepstorff
P
P
D000595:Amino Acid Sequence; D018554:Avena / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D017124:Conserved Sequence; D003488:Cyanogen Bromide; D004220:Disulfides / Q000032:analysis; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D055315:Prolamins; D017386:Sequence Homology, Amino Acid; D012995:Solubility; D014357:Trypsin
D004220:Disulfides; D010446:Peptide Fragments; D010940:Plant Proteins; D055315:Prolamins; D014357:Trypsin; D003488:Cyanogen Bromide