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, cilt.68, ss.685-693, 2004 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 68 Konu: 3
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1271/bbb.68.685
  • Sayfa Sayıları: ss.685-693


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.