Esterase and lipase activity in Jatropha curcas L. seeds
| Autor: | Georg Gübitz, I. Ncube, Walter Steiner, Ruth Staubmann, J. S. Read |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Tributyrin
Triacylglycerol lipase Bioengineering Applied Microbiology and Biotechnology Esterase Substrate Specificity chemistry.chemical_compound Hydrolysis Nuts Lipase Chromatography biology Esterases Temperature Substrate (chemistry) General Medicine Hydrogen-Ion Concentration biology.organism_classification Isoelectric point chemistry Biochemistry Metals Seeds biology.protein Jatropha curcas Biotechnology Half-Life |
| Zdroj: | Journal of biotechnology. 75(2-3) |
| ISSN: | 0168-1656 |
| Popis: | Two new esterases (JEA and JEB) and a lipase (JL) were extracted from the seeds of Jatropha curas L. Lipase activity was only found during germination of the seeds and increased to a maximum after 4 days of germination. All enzymes were found to be most active in the alkaline range at around pH 8 and the purified (fractionated precipitation with ethanol and gel filtration) esterases were very stable at high temperatures. The molecular weight (SDS-PAGE) of both esterases was determined to be 21.6-23.5 kDa (JEA) and 30.2 kDa (JEB) and the isoelectric point was 5.7-6.1 for esterase JEA and 9.0 for esterase JEB. Most ions caused a negative influence on the activity of both esterases. Using p-nitrophenyl butyrate as a substrate JEA showed a K(m) of 0.02 mM and a v(max) of 0.26 micromol mg(-1) min(-1). Under the same conditions JEB showed a K(m) of 0.07 mM and a v(max) of 0.24 micromol mg(-1) min(-1). Both esterases hydrolyzed tributyrin, nitrophenyl esters up to a chain length of =C4 and naphtylesters up to a chain length =C6. In transesterification reactions, JL was found to be most active at very low water activities (0.2) and in high water activities, the lipase hydrolysed triglycerides into conversions above 80%. The lipase hydrolysed both short chain and long chain triglycerides at about the same rate but was inactive on alpha-methylbenzyl acetate. JL is a potentially useful biocatalyst in the hydrolysis of triglycerides in organic solvents. |
| Databáze: | OpenAIRE |
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