2Research Institute of Physicochemical Medicine, ul. Malaya Pirogovskaya 1a, 119992 Moscow, Russia; fax: (499) 255-2846; E-mail: email@example.com
3Biological Faculty, Lomonosov Moscow State University, 119991 Moscow, Russia; fax: (495) 939-4309; E-mail: Saliva1@yandex.ru
* To whom correspondence should be addressed.
Received February 27, 2010; Revision received March 27, 2010
Preparation and purification of a recombinant protein are described along with characteristics of its specific (for ε-(γ-Glu)-Lys and D-dimer substrates) and nonspecific (for L-γ-Glu-pNA) isopeptidase activities; the absence of peptidase function for α-(α-Glu)-Lys substrate is noted. It is shown that the protein exhibits muramidase (cell walls of Micrococcus lysodeikticus) and specific glycosidase activities. The latter was determined towards the fluorogenic substrate 4-methylumbelliferyl-tetra-N-acetyl-β-chitotetraoxide. Antimicrobial activity of recombinant destabilase-lysozyme protein (recDest-Lys) and its 11-membered amphipathic peptide was revealed towards cells of the strict anaerobic Archaean Methanosarcina barkeri, whose cell walls contain no murein. Possible mechanisms of the effect of recDest-Lys on these cells are discussed.
KEY WORDS: endo-ε-(γ-Glu)-Lys- and exo-ε-(γ-Glu)-Lys-isopeptidolysis, specific glycosidase activity, 4-methylumbelliferyl-N-acetyl-β-chitotetraoxide, muramidase activity, antibacterial activity, Methanosarcina barkeri