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Extracellular Lytic Enzymes of Myxococcus virescens
Author(s) -
HASKÅ GUNO
Publication year - 1974
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1974.tb03700.x
Subject(s) - enzyme , chemistry , muramic acid , biochemistry , chromatography , endopeptidase , cell wall , centrifugation , alanine , lysis , lysine , amino acid , micrococcus , enzyme assay , peptidoglycan , bacteria , biology , genetics
An easy and rapid method for the purification of a bacteriolytic endopeptidase produced by Myxococcus virescens is described. The bacteria were grown in casitone media and the cells were sedimented by centrifugation. About 1.2 g of montmorillonite were added per liter of cell‐free culture solution. The clay was sedimented by centrifugation and the enzyme was then eluted by 0.05 M Na‐phosphate buffer pH 6.0, containing 0.4 M NaCl. The enzyme was diluted with water and chromatographed on carboxymethyl‐cellulose columns. The purified enzyme liberated free amino groups but no reducing sugars or N‐acetylhexosamines when acting on purified N‐acetylated cell walls of Micrococcus lysodeikticus . Analysis of N‐ and C‐terminal amino acids in the digestion products showed that the enzyme had liberated about 110 nmoles of lysine ε‐amino groups and 60 nmoles of alanine carboxyl groups per mg of cell wall. When it acted on a bisdisaccharide pentapeptide dimer isolated from M. lysodeikticus cell walls, it cleaved about 30% of the alanyl‐lysine linkages. Consequently the enzyme was an alanyl‐lysine endopeptidase. It had no muramyl‐alanine amidase activity.