Abstract

ZAPATA-ZAPATA, Arley David; HOURS, Roque Alberto  and  CAVALITTO, Sebastián Fernando. Protopectinase-se from Geotrichum klebahnii: Studies of the adsorption and pectin-solubilization capacity. Dyna rev.fac.nac.minas [online]. 2017, vol.84, n.201, pp.216-223. ISSN 0012-7353.  https://doi.org/10.15446/dyna.v84n201.52800.

Protopectinase SE (PPase-SE) is a polygalacturonase produced by Geotrichum klebahnii with the capacity to liberate pectin through protopectin hydrolysis. The protopectin cleavage is a typical heterogeneous-catalysis reaction whose interaction between the enzyme and the protopectin substrate from lemon albedo along with the release of the pectin-reaction product were the objectives of this investigation. The interaction between PPase-SE and protopectin depended on the particle size and the structure of the substrate as well as on the nature of the buffer. The adsorption kinetics follows, for small particles, a Langmuir isotherm pattern. The reaction exhibited Michaelis-Menten kinetics, giving respective apparent-Km and Vmax values of 30.2 g/l and 57.3 g/l.h. The better results in enzyme adsorption and pectin releasing were obtained with citrate and citrate-phosphate buffers. This report constitutes the first investigation in pectin solubilization involving a model for the substrate-binding mechanism within the pectinase-protopectinase system.

Keywords : Pectin; protopectin; protopectinase-SE; Langmuir isotherm; Michaelis-Menten.

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