Purification and characterization of a hyaluronidase associated with a temperate bacteriophage of group A, type 49 streptococci

Abstract

Urea treatment of a temperate bacteriophage from a type 49 strain of group A streptococcus (Streptococcus pyogenes) followed by ammonium sulfate fractionation, ion exchange, and affinity chromatography of solubilized proteins provided for the recovery (12%) and purification (44-fold) of the phage-associated hyaluronidase. The molecular weight of the homogeneous, purified enzyme was estimated to be 71,000 by polyacrylamide gel electrophoresis (in the presence of sodium dodecyl sulfate) and 75,000 by gel filtration with Sephacryl S-200. The enzyme has a pH optimum of 5.5, a Vmax of 0.1 absorbance unit/min per microgram of protein, and a Km of 4.8 X 10(-2) mg/ml with umbilical cord hyaluronic acid as substrate. Of the cations tested, calcium and magnesium were the only effectors of the enzyme. The enzyme is a glycoprotein (7.25% carbohydrate) containing glucose, galactose, and glucosamine. Analysis of the amino acid composition revealed a predominance of acidic amino acids and a relatively high content of cysteine. The partial specific volume, estimated from the amino acid and sugar analyses, was 0.725 cm3/g.