Isolation, purification and partial characterization of a lectin from the leaves of Annona squamosa L.

Date

10-2005

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Marivic S. Lacsamana

Co-adviser

Veronica C. Sabularse

Abstract

ABSTRACT

MOSQUEDA, SONNY JR. M. University of the Philippines Los Banos, Octobet 2005. Isolation, Purification and Partial Characterization of a Lectin from the Leaves of. Annona squamosa L.

ADVISER: Dr. Marivic S. Lacsamana

A lectin was isolated from mature leaves of Annona squamosa L., a component of a locally popular concoction tea of seven herbs otherwise known as "pito-pito".

Survey of potential lectin activities of the leaves of the seven herbs namely, banaba or Lagerstroemia speciosa, bayabas or Psidium guajava, mangga or Mangifera indica, alagaw or Premna odorata Blancor, lagundi or Vitex negundo, pandas or Pandanus tectorius, and atis or Annona squamosa L. revealed their hemagglutinating properties in one or more blood types. However, the lectin activity detected in the leaves of Annona squamosa L. was considerably higher than those detected in the other leaf samples.

By comparing the lectin activities of Annona squamosa L. leaves at different stages of maturity, mature leaves were gathered and from them was isolated the lectin, owing to their relatively higher activity than the young and semi-mature leaves.

Isolation was done using 0.02 M phosphate buffered saline (pH 7.2) with G.15 M NaCI. The lectin was purified by 90% ammonium sulfate fractionation, dialysis, and gel filtration chromatography using Sephadex G-150. Homogeneity of the lectin was confirmed by polyacrylamide gel electrophoresis under non-denaturing conditions.

The Annona squamosa L. leaf lectin is non-blood type specific, equally agglutinating human erythrocytes of types A, B, AB and 0. It is not inhibited by 200 mM and 1000 mM concentrations of D(+)-glucose, D(+)-mannose, D(+)-xylose, D(+)-galactose, fucose and D(+)-glucosamine. Carbohydrate analysis using periodic acid Schiff staining and phenol-sulfuric acid method suggested the glycoprotein nature of the purified lectin with 1.23 mg of total sugar per milliliter of the isolate.

The molecular weight of the purified lectin was approximated through gel filtration chromatography using Sephadex G-200 to be 104.36 KD.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2005 C4 M68

Document Type

Thesis

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