Isolation and purification of convicilin of mungbean (Vigna radiata (L.) Wilczek)

Date

4-2005

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Evelyn Mae T. Mendoza

Co-adviser

Marivic Lacsamana

Abstract

RABANZO, ICRISTEL MAE M. 2005. ISOLATION AND PURIFICATION OF CONVICILIN OF MUNGBEAN [Vigna radiata (L.) Wilzeck]. University of the Philippines Los Banos. Bachelor of Science in Chemistry.

Adviser: Evelyn Mae Tecson-Mendoza, PhD.

Total globulins were extracted from defatted mungbean meal using 0.1 M potassium phosphate buffer containing 0.4 M NaCI. An initial experiment showed that with 80% ammonium sulfate fractionation of total globulins, the convicilin (64 k) and the vicilin or 8S globulin (48 k) were present in the supernatant, whereas the 11S globulin or legumin and some vicilin were present in the precipitate. Gel filtration chromatography resulted in isolation and partial purification of two major peaks. The first peak was vicilin which coeluted with legumin. The second peak was convicilin with some vicilin. Further purification of the convicilin protein was done in three trays: (1) a combination of ammonium sulfate fractionation, gel filtration and hydroxyapatite column chromatography, (2) ammonium sulfate fractionation-gel filtration chromatography-ammonium sulfate fractionation combination, and (3) 90% ammonium sulfate fractionation of vicilin convicilin fractions from gel filtration chromatography and of the 80% ammonium sulfate supernatant. The results showed that on hydroxyapatite column chromatography, the fractions showed vicilin with 48 k and 64 k bands as well as fractions with only the 48 k bands. In the second procedure, both vicilin and convicilin bands were observed in the precipitates and supernatants of ammonium sulfate fractions at 25-80% saturation. With the third procedure, the 48 k band was shown in the 90% ammonium sulfate supernatant while the 90% ammonium sulfate precipitate still contained the 48 k and 64 k bands. This study showed that mungbean has convicilin and that there are two types of vicilin: one with the 48 k band subunit and the second, with both 48 k and 64 k subunits, the 64 k subunit being the convicilin.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2005 C4 R33

Document Type

Thesis

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