Isolation and characterization of the K6 type yeast killer protein

Microbios. 1999;99(394):161-72.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Electrophoresis, Polyacrylamide Gel
  • Fungal Proteins / chemistry
  • Fungal Proteins / isolation & purification*
  • Glycoproteins / chemistry
  • Glycoproteins / isolation & purification*
  • Hydrogen-Ion Concentration
  • Isoelectric Point
  • Kluyveromyces / chemistry*
  • Kluyveromyces / metabolism
  • Microbial Sensitivity Tests
  • Mycotoxins / chemistry
  • Mycotoxins / isolation & purification*
  • Phenotype
  • Saccharomyces cerevisiae / growth & development
  • Temperature


  • Fungal Proteins
  • Glycoproteins
  • Mycotoxins