An 8 kDa Methionine-Rich Protein from Soybean (Glycine max) Cotyledon: Identification, Purification, and N-Terminal Sequence

Abstract

The genes encoding methionine-rich proteins (MRP) in seeds are candidates for overexpression to enhance the nutritional quality of legume proteins, which are relatively deficient in methionine. Our previous work on soybean seed localized the MRP in the albumin fraction, and the present work further localized them in the low molecular weight fraction (LMW) of albumin. Enrichment of the albumin fraction for LMW proteins by heparin-Sepharose affinity chromatography before resolution on 2D SDS-PAGE and labeling of methionine-containing proteins with [1-14C]iodoacetate resulted in identification of three methionine-rich 8 kDa proteins with different pI values. The most acidic of the three (2D-1) was recovered for amino acid analysis and partial protein sequencing. 2D-1 had 8.6% methionine, 11.4% lysine, and high amounts of glutamic acid and aspartic acid. This work lays the groundwork for cloning of the gene encoding 2D-1, its eventual overexpression in soybean seed, and elucidation of a possible biological role for 2D-1 and related proteins.

Source or Periodical Title

Journal of Agricultural and Food Chemistry

ISSN

218561

Page

2930-2935

Document Type

Article

Subject

Methionine-rich protein, Soybean (Glycine max)

This document is currently not available here.

Share

COinS