Isolation and characterization of the K6 type yeast killer protein

Izgu, F
Altinbay, D
Sagiroglu, AK
The optimum production of K6 type yeast killer protein by Kluyveromyces fragilis NCYC 587 occurred at pH 4.0-4.4 and at 22-24 degrees C in a killer-zone assay test. The K6 killer protein was concentrated by acetone precipitation of the culture supernatant and purified by native polyacrylamide rod gel electrophoresis. The protein migrated as a single band on discontinuous gradient SDS polyacrylamide gel electrophoresis and had a molecular weight of 42,313. The isoelectric point of the K6 type protein was determined at pH 5.97 by high voltage vertical polyacrylamide gel electrofocusing. Western blot analysis revealed that the K6 killer toxin was a nonglycosylated protein.


Isolation and characterization of the K5-type yeast killer protein and its homology with an exo-beta-1,3-glucanase
Izgu, F; Altinbay, D (Informa UK Limited, 2004-03-01)
K5-type yeast killer protein in the culture supernatant of Pichia anomala NCYC 434 cells was concentrated by ultrafiltration and purified to homogenity by ion-exchange chromatography with a POROS HQ/M column followed by gel filtration with a TSK G2000SW column. The protein migrated as a single band on discontinous gradient SDS-PAGE and had a molecular mass of 49000 Da. The pI value of the K5-type killer protein was measured at pH 3.7 by high voltage vertical gel electrofocusing. The result of an enzyme immu...
Isolation characterization of the K4 type yeast killer toxin
Acun, Tolga; İzgü, Kadri Fatih; Department of Biology (2003)
Killer yeasts secrete polypeptide toxins which kill sensitive cells of their own species and frequently those of other species and genera of yeasts. These protein compounds are designated as killer toxins. Also killer toxins of certain yeast strains have potential growth inhibitory activity on gram-positive pathogenic bacteria and plant pathogenic fungi. The yeasts are immune to their own killer protein. The killer phenomenon can be utilized for the protection of fermentation process against contaminating y...
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Khalily, Mohammad Aref; Demir, Ayhan Sıtkı; Department of Chemistry (2011)
The synthesis of enantiopure compounds can be achieved by using dehydrogenases as biocatalysts. For instance, reduction reactions of prochiral compounds (ketones, aldehydes and nitriles) into chiral compounds can be achieved by dehydrogenases. These dehydrogenases are cofactor dependent where cofactor is Nicotinamide Adenin Dinucleotite having some restrictions that confines usage of dehydrogenases in organic synthesis including instability of cofactor in water and high cost. Therefore, suitable recycling m...
Partial purification and characterization of neutral trehalase from commercial baker's yeast, Saccharomyces cerevisiae
Yarar, S; Hamamcı, Haluk; Bakir, U (2000-12-01)
The neutral trehalase of a commercial baker's yeast (S. cerevisiae) strain has been partially purified using ammonium sulfate fractionation and DEAE-cellulose column chromatography techniques. Trehalase was precipitated between 35-50% ammonium sulfate saturation and approximately 5-8 fold purification was achieved. The yeast cAMP-dependent protein kinase was also precipitated in the same fraction and these two proteins were separated by DEAE-cellulose column chromatography. Trehalase became totally inactive...
Citation Formats
F. Izgu, D. Altinbay, and A. Sagiroglu, “Isolation and characterization of the K6 type yeast killer protein,” MICROBIOS, pp. 161–172, 1999, Accessed: 00, 2020. [Online]. Available: