CHARACTERIZATION OF UREASE FROM SPOROSARCINA-UREAE


Mccoy D., Cetın A. G., Hausınger R.

ARCHIVES OF MICROBIOLOGY, cilt.157, ss.411-416, 1992 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 157
  • Basım Tarihi: 1992
  • Doi Numarası: 10.1007/bf00249097
  • Dergi Adı: ARCHIVES OF MICROBIOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.411-416
  • Anahtar Kelimeler: UREASE, SPOROSARCINA-UREAE, NICKEL, ALKALINE STABLE, ENZYME ACTIVATION, KLEBSIELLA-AEROGENES UREASE, JACK BEAN UREASE, UREAPLASMA-UREALYTICUM, ACID UREASE, PURIFICATION, SEQUENCE, GENES, PROTEINS
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

Alkaline stable (pH 7.75-12.5) urease from Sporosarcina ureae was purified over 400-fold by ion exchange and hydrophobic interaction chromatography. The cytoplasmic enzyme was remarkably active with a specific activity of greater than 9300-mu-mol urea degraded min-1 mg protein-1 at pH 7.5, where it has optimal activity. Although S. ureae is closely related to Bacillus pasteurii, known to possess a homopolymeric urease containing 1 nickel per subunit [M(r) = 65000], the S. ureae enzyme is comprised of three subunits [apparent M(r) = 63100 (alpha), 14500 (beta), and 8500 (gamma)] in an estimated alpha-beta-gamma-2, stoichiometry and contains 2.1 +/- 0.6 nickel ions per alpha-beta-gamma-2 unit as measured by atomic absorption spectrometry. Stationary phase cultures sometimes possessed low levels of urease activity, but the specific activity of cell extracts of partially purified urease preparations from such cultures could be elevated by heat treatment, dilution, or dialysis to values comparable to those observed in samples from exponentially grown cells.