Physicochemical and structural characterization of Lima Bean (Phaseolus lunatus) globulins

CHEL-GUERRERO, L., SCILINGO, A.A., GALLEGOS TINTORÉ, S., DÁVILA, G., AÑÓN, M.C.

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

Año: 2007 vol. 40 p. 1537 - 1544

0023-6438

personal AbstractA globulin fraction from Phaseolus lunatus have been isolated and characterized. The fractionation scheme used allowed to obtain aGlobulin partially purificated. Globulin purification by ultracentrifugation allowed to isolate three peaks with different sedimentationcoefficient, while gel filtration chromatography yielded two species, I and II, which were later identified as 11S and 7S globulins,respectively. Species II, 7S globulin from P. lunatus, seems to have a molecular mass of 72 kDa and to be constituted by polypeptides of34–36, 25–27 and 16–18 kDa without intermolecular disulfide bonds. These polypeptides would present certain heterogeneity, assuggested by the results of isoelectric focusing and electrophoresis analyses. This protein exhibited some particular features, including alower molecular mass and higher thermal stability than typical vicilins. Species I, with a molecular mass of 336 kDa, would be constitutedby subunits of 53–55 and 40–41 kDa formed by smaller polypeptides (around 30 and 20 kDa) linked by disulfide bonds. These features,together with the existence of basic and acid polypeptides in the molecule, would confirm that species I is a globulin of the legumins, 11Sglobulins or a-conglutin family.r 2006 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.