Peptide with Angiotensin I-Converting Enzyme Inhibitory Activity from Hydrolyzed Corn Gluten Meal

Corn gluten meal (CGM) was hydrolyzed by Alcalase after starch removal of CGM was applied as a pretreatment. A new inhibitory peptide for angiotensin I-converting enzyme (ACE) was isolated from the hydrolysate of CGM with the use of Bio-Rad P-2 gel filtration and followed by reverse-phase high-performance liquid chromatography (RP-HPLC). The sequence of the active peptide was determined to be Ala–Tyr after the application of amino acid analysis and HPLC/MS. The IC50 of the peptide was 14.2 µM, and it was not affected by preincubation with 30 mU of ACE at 37 °C for 3 h. Ala–Tyr also exerted antihypertensive effects after oral administration to spontaneously hypertensive rats. A maximal reduction of systolic blood pressure of 9.5 mmHg was observed 2 h after oral administration of Ala–Tyr at doses of 50 mg/kg.