Isolation and partial purification of the major storage protein in winged bean [Psophocarpus tetragonolobus (L.) DC] with bioactive peptides exhibiting ace inhibitory activity

Date

4-2009

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Mary Ann O Torio

Co-adviser

Roberta N. Garcia

Abstract

CYNDE C. VALEZA. University of the Philippines Los Banos, April 2009. Isolation and Partial Purification of the Major Storage Protein in Winged Bean [Psophocarpus tetragonolobus (L) DC)] with Bioactive Peptides exhibiting ACE Inhibitory Activity.

Adviser: Mary Ann 0. Torio, Ph.D.

Total soluble proteins of winged bean var. Gloria, was extracted using a buffer mixture of Tris-HC1 and phosphate buffer. The major storage protein was then purified using ammonium sulfate fractionation, hydrophobic interaction chromatography and gel filtration chromatography. The estimated molecular weight of the major storage protein was 19175.6 Da on SDS-PAGE. The protein concentration was 4.10 mg/ml. In silico analysis was done to determine if the protein sequence of the major storage protein in winged bean contains peptides exhibiting ACE inhibitory activity and anti-hypertensive activity. Peptide sequences VK, MY, and FQP were found. The second major protein was also analyzed and found to contain IA and IY. The partially purified protein was digested using thermolysin. The ACE inhibitory activity of the partially purified protein and the digested protein at an hour and 24 hours digestion time with thermolysin to protein v/v ratio of 8:1 was determined. The ACE activity was 1.34 x 10' U. The digests were found to inhibit the ACE at one hour and 24 hour digestion time with percent inhibitions 88.70 and 92.47. The ACE inhibitory activities were 1.19 x 10"3 U and 1.01 x 10 U. The undigested protein also inhibited the ACE having 37.24 percent inhibition. Other low molecular weight proteins or denatured proteins may have caused this. Although the other proteins were digested, it was assumed that the peptides came from the major storage protein having the highest percent concentration (17.37%) from densitometric analysis.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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