Partial amino acid sequences of a peptide induced by Fe deficiency in barley roots

Abstract

Several peptides induced by Fe deficiency in barley roots were observed on two-dimensional gel electrophoresis (2D-PAGE). Among them, a 36 kD peptide was found to be induced most strongly by Fe deficiency. The induction of the 36 kD peptide seemed to be specific to the Fe deficiency since it was not induced by the other various nutrient stresses, i.e., B excess, B deficiency, Cu excess, Cu deficiency, Mn excess, Mn deficiency, Zn excess and Zn deficiency. The 36 kD peptide was collected by 2D-PAGE, and was sequenced. However, its N-terminal was blocked. The peptide was then enzymatically digested with either V8 protease or lysylendopeptidase. The partial amino acid sequences of the resultant peptides were determined as “DHTELNELYSFDTATS(X)W(X)L”, “AFVLDT” and “VTINQ”. This 36 kD peptide is the first peptide in which a partial amino acid was sequenced under nutrient deficiency stress.