Purification and Characterization of an alpha-Mannosidase from the Tropical Fruit Babaco (Vasconcellea x Heilbornii Cv. Babaco)
2008 (English)In: Journal of Agricultural and Food Chemistry, ISSN 0021-8561, Vol. 56, no 22, 10872-10878 p.Article in journal (Refereed) Published
An alpha-mannosidase (EC 184.108.40.206) present in the lyophilized latex of babaco (Vasconcellea heilbornii) has been purified to apparent homogeneity by native PAGE. The purification involves a three-step procedure with successive anion exchange with 0 Sepharose HP, lectin affinity chromatography using ConA Sepharose 4B, and gel filtration using Superdex 200 prep grade. The molecular mass was determined to be in the range of 260-280 kDa by Superdex 200 prep grade gel filtration, and isoelectric focusing showed a pI range between 5.85 and 6.55, suggesting different glycosylated isoforms. The optimal temperature for the alpha-mannosidase was determined to lie between 50 and 60 degrees C, and the optimal pH was 4.5 at 50 degrees C. The K-m value for p-nitrophenyl alpha-mannopyranoside (pNPM) was found to be 1.25 mM and the V-max, 2.4 mu kat mg(-1) at 50 degrees C and 1.94 mu kat mg(-1) at 40 degrees C. The pure alpha-mannosidase was specific for mannose and did not display activity for any other tested synthetic substrates.
Place, publisher, year, edition, pages
2008. Vol. 56, no 22, 10872-10878 p.
alpha-Mannosidase, babaco, latex, purification, characterization, subunit composition
IdentifiersURN: urn:nbn:se:uu:diva-107031DOI: 10.1021/jf800857kISI: 000261056700065OAI: oai:DiVA.org:uu-107031DiVA: diva2:227583