Isolation, purification and characterization of the major storage protein in cowpea (Vigna unguiculata) seed with bioactive peptides exhibiting anti-angiotensin I-converting enzyme activity

Date

4-2013

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Mary Ann O. Torio

Restrictions

Restricted: Not available to the general public. Access is available only after consultation with author/thesis adviser and only to those bound by the confidentiality agreement.

Abstract

In silico analysis of the amino acid sequence of the major storage protein (7S globulin) of cowpea (Vigna unguiculata) seed revealed bioactive peptides with antihypertensive activity. The major stirageprotein of cowpea was isolated using 50 mM sodium borate buffer at pH 8.0 and was further purified using ammonium sulfate precipitation, dialysis and gel filtration chromatography. The total protein content of the crude extract and the partially purified protein using the Bradford method was 6.0 mg/ml and 2.04 mg/ml respectively.The partially purified protein was subjected to proteolytic digestion using pepsin which was able to hydrolyze the pure protein in 24 hours. Peptic hydrolysate was found to inhibit the activity of angiotension I-converting enzyme (ACE) by 85.48% and was observed to have IC50 value of 0.22 mg/ml. The protein hydrolysate was further subjected to reversed phhase-high performance liquid chromatograpy (RP-HPLC) to determine the peptides responsible for anti-ACE activity. There was only one fraction collected that exhibited an inhibitory activity of 90.02% against ACE and an IC50 value of 0.07 mg/ml. The amino acids in the peptide triggering the antihypertensive property of 7S globulin were determined through thin layer chromatography (TLC). The bioactive peptide was possibly a dipeptide with probable sequences of YG or GY, AF or FA, and GF or FG.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2013 C42 /D45

Document Type

Thesis

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