Isolation and characterization of the K5-type yeast killer protein and its homology with an exo-beta-1,3-glucanase


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Izgu F., Altinbay D.

BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, vol.68, no.3, pp.685-693, 2004 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 68 Issue: 3
  • Publication Date: 2004
  • Doi Number: 10.1271/bbb.68.685
  • Title of Journal : BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY
  • Page Numbers: pp.685-693
  • Keywords: killer yeast, Pichia anomola, K5 type killer protein, exo-beta-1,3-glucanase, KLUYVEROMYCES-LACTIS, POLYACRYLAMIDE-GELS, HANSENULA-MRAKII, CELL-WALL, TOXIN, PLASMIDS, IDENTIFICATION, PURIFICATION, STRAIN, MODE

Abstract

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 immuno assay revealed that it was a glycosylated protein. Its internal amino acid sequencing yielded the sequences LNDFWQQGYHNL, IPIGYWAFQLLDNDPY, and YGGSDYGDVVIGIELL, which are 100% identical to exo-beta-1,3-glucanase (accession no. AJ222862) of Pichia anomala (strain K). The purified protein was highly stable at pH values between 3 and 5.5 and temperatures up to 37degreesC.