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| Author(s): |
Tamara Rezende de Azevedo
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2000-04-28 |
| Examining board members: |
Clélia Ferreira;
Osvaldo Marinotti;
Ana Claudia Rasera da Silva
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| Advisor: | Clélia Ferreira |
| Abstract | |
The Lepidoptera Diatraea saccharalis has three soluble digestive β-glycosidases. They were resolved by a combination of chromatographic steps, using Econo Pac Q (low-pressure system), Mono Q , Phenyl Superose, Superose 12 and Mono P (FPLC system) columns. Two enzymes called E1 and E2 were purified to homogeneity. The third (E3) was semi-purified. Hydrophobic columns are the only ones able to resolve the three β-glycosidase activities. The relative molecular weights (SDS PAGE}, pH optimum and pi values were, respectively: E1 , 58 K, 6.7, 7.5; E2, 61 K, 6.3, 7.4; E3, 61 K, 7.2, 7.4. The enzymes have four sub-sites for glucon binding in their active sites. They have broad substrate specificity to hydrolyze synthetic substrates, disaccharides, oligosaccharides and plant toxic glucosides. E1 may have the physiological role of hydrolyzing oligosaccharides derived from hemicellulose digestion. E2 may be responsible for glycolipid digestion and E3 seems to be the main enzyme that digests disaccharides. (AU) | |