Abstract: Albumin is the major protein in almond. In this experiment, we purified and structurally characterized 2S-albumin from Shache No.1 almond (SC-1) from Xinjiang. Crude albumin extract was obtained from almond by repeated precipitation with organic solvents and then fractionated chromatographically on Q Sepharose FF to obtain 2S-albumin. By HPLC-MS analysis, the accurate molecular mass of 2S-albumin was determined to be 31.40 kD, which was separated into two bands (18.0 and 19.5 kD) in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), indicating that it was composed of two distinct subunits connected through disulfide bonds. In 2S-albumin, the contents of glutamic acid, aspartic acid and arginine residues were relatively high, and its dominant secondary structure was β-sheet (65.9%). The carbonyl group content of 2S-albumin was 4.45 nmol/mg, the active thiol group content was 39.95 μmol/g, the total thiol group content was 57.11 μmol/g, the surface hydrophobicity was 23.45 μg, and the denaturation temperature was 43.3 ℃. These results can provide a theoretical support for the development and utilization of Xinjiang grown almond.

Key words: almond, 2S-albumin, purification, structure characteristics