Purification and Characterization of an endo-Polygalacturonase from the Gut of West Indies Sugarcane Rootstalk Borer Weevil (Diaprepes abbreviatus L.) Larvae |
| |
Authors: | Hamed Doostdar T.Gregory McCollum Richard T Mayer |
| |
Affiliation: | aU.S. Department of Agriculture, Agricultural Research Service, U.S. Horticultural Research Laboratory, 2120 Camden Road, Orlando, FL 32803-1419 USA |
| |
Abstract: | An endo-polygalacturonase (PG) (EC:3.2.1.15) with a pI of 9.4 and an Mr of 44,500 was purified to electrophoretic homogeneity from the gut of West Indies sugarcane rootstalk borer weevil (Diaprepes abbreviatus L.) larvae. Hydrolytic activity was maximal in 150 mM sodium acetate, pH 5.5, at 30°C. Kinetic determinations yielded an apparent Km of 3.68 mg polygalacturonic acid (PGA)/ml and a Vmax of 283 μmol galacturonic acid/min/mg protein for PGA. Enzymatic activity was inhibited by a polygalacturonase inhibitor protein from “Hamlin” orange flavedo. The purified protein does not appear to be glycosylated, and its N-terminal sequence showed no homology to any PG protein sequences in data banks. |
| |
Keywords: | Citrus herbivory insect N-terminal sequence polygalacturonase inhibiting protein PGIP plant defense |
本文献已被 ScienceDirect 等数据库收录! |