Isolation, purification, and characterization of a killer protein from Schwanniomyces occidentalis
| Autor: | Wen-Bao Chen, Yuh-Fehng Han, Shenq-Chyi Chang, Shung-Chang Jong |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Protein subunit Saccharomyces cerevisiae Molecular Sequence Data chemical and pharmacologic phenomena medicine.disease_cause Applied Microbiology and Biotechnology Binding Competitive Microbiology Fungal Proteins Laminarin chemistry.chemical_compound Plasmid Polysaccharides medicine Amino Acid Sequence Mannan Fungal protein Ecology biology Toxin Hydrogen-Ion Concentration Mycotoxins biology.organism_classification Physiology and Biotechnology Yeast Killer Factors Yeast Molecular Weight Protein Subunits Phenotype chemistry Biochemistry Fermentation Saccharomycetales Food Technology Food Science Biotechnology Plasmids |
| Zdroj: | Applied and environmental microbiology. 66(12) |
| ISSN: | 0099-2240 |
| Popis: | The yeastSchwanniomyces occidentalisproduces a killer toxin lethal to sensitive strains ofSaccharomyces cerevisiae. Killer activity is lost after pepsin and papain treatment, suggesting that the toxin is a protein. We purified the killer protein and found that it was composed of two subunits with molecular masses of approximately 7.4 and 4.9 kDa, respectively, but was not detectable with periodic acid-Schiff staining. A BLAST search revealed that residues 3 to 14 of the 4.9-kDa subunit had 75% identity and 83% similarity with killer toxin K2 fromS. cerevisiaeat positions 271 to 283. Maximum killer activity was between pH 4.2 and 4.8. The protein was stable between pH 2.0 and 5.0 and inactivated at temperatures above 40°C. The killer protein was chromosomally encoded. Mannan, but not β-glucan or laminarin, prevented sensitive yeast cells from being killed by the killer protein, suggesting that mannan may bind to the killer protein. Identification and characterization of a killer strain ofS. occidentalismay help reduce the risk of contamination by undesirable yeast strains during commercial fermentations. |
| Databáze: | OpenAIRE |
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