Structural studies on wheat (Triticum aestivum) proteins lacking phenylalanine and histidine residues

Abstract

1. Three very similar proteins, each of approx. 120 amino acid residues but lacking phenylalanine and histidine, were isolated from wheat (Triticum aestivum) flour in sufficient quantities for further structural studies. 2. Each protein, after reduction and carboxymethylation, was cleaved at the three methionine residues with CNBr to give four major peptides, which were isolated. These peptides are suitable for future sequencing studies, as the sums of their amino acid compositions are in good agreement with those of the whole proteins. 3. The N- and C-terminal peptides were identified. 4. Evidence from amino acid analyses, N-terminal amino acids and electrophoretic mobilities of the peptides suggests a high degree of homology between the proteins. Definite differences in C-terminal amino acids and the number of glycine, alanine and arginine residues were found in the C-terminal peptides.

N-terminal amino acid sequence of wheat proteins that lack phenylalanine and histidine residues

“…The sequence of residues 19-23 was determined by dansyl-Edman degradation. Amino acid analysis of peptide C4 from peptide M-CNBr-4 supported the assignments, and also located the homoserine residue known to be C-terminal in the CNBr-4 peptides (Redman, 1975).…”

“…The 'rapid Edman degradation' procedure of Gray and Smith as described by Gray (1972) was used. Subsequent dansylation and detection of derivatives on polyamide layers were as described by Redman (1975).…”

“…(1976) 153, 5. The nature of such evidence is stated in the text of this present communication.The CNBr peptides from three wheat albumins that lack phenylalanine and histidine residues were partially characterized by Redman (1975). The peptides from the N-terminal regions of these three proteins were identical in integral amino acid composition, in electrophoretic mobility and in possessing N-terminal serine.…”

“…The nomenclature in the previous paper (Redman, 1975) is retained, the N-terminal CNBr peptides being termed S-CNBr-4, M-CNBr-4 and F-CNBr-4, where S, M and F are the proteins.…”

Hb Helsinki: a Variant with a High Oxygen Affinity and a Substitution at a 2,3-DPG Binding Site (<i>β</i>82 [EF6] Lys→Met)

“…2 Interconversion takes place on the analyser column [32]. fragment, which gave a specific staining reaction for His, was detected in a finger-print of the abnormal chain only ( fig.…”