[Renaturation of bacterial metalloproteinases]

After denaturation by phenol or acid ethanol bacterial metalloproteinases secreted by Bacillus thermoproteolyticus and Bacillus megaterium cells can be renatured by dissolution in 99.7% formic acid with subsequent dilution of the solution and its neutralization with an appropriate amount of an alkali. Renaturation is optimal at pH 9.0 in the presence of 30% glycerol as stabilizer, Ca2+ and Zn2+ ions needed for the formation of a native structure and reconstitution of the enzyme catalytic center. The active enzyme yield is 60-80%. Reactivated metalloproteinases retain their enzymatic properties, amino acid composition and molecular mass. Under these conditions autolysis of metalloproteinases does not significantly influence their renaturation.