Purification of staphylococcal coagulase

BIOCHEMICAL STUDIES ON STAPHYLOCOAGULASE AND AN ALLIED PHOSPHATASE ACTIVITY

Inniss, William E. (Michigan State University, East Lansing) and Charles L. SanClemente. Biochemical studies on staphylocoagulase and an allied phosphatase activity. J. Bacteriol. 83:941-947. 1962.-The present investigation was undertaken to determine whether the reported correlation between the coagulase and phosphatase activity of the staphylococci was functional. Staphylococcus aureus, phage-propagating strain 70, grown in brain heart infusion was the source of the purified coagulase. The concomitant phosphatase activity, measured spectrophotometrically at 400 mmu using p-nitrophenylphosphate as substrate, showed a parallel decrease during thermal inactivation at 37 and 56 C. Anion-exchange chromatography and electrophoresis using starch, starch gel, and paper as stabilizing media failed to separate the two activities. Since iodoacetate, ethylenediamine-tetraacetate, fluoride, azide, and p-chloromercuribenzoate always exerted different degrees of inactivation, apparently the same mechanism was not involved. This supposition was supported by subsequent saturation of the phosphatase with excess substrate (100-fold K(s) value) and the demonstration that under this condition coagulase was not inhibited. During this purification process, comparable increases in specific activity occurred for both coagulase and phosphatase, indicating the presence of a common protein carrier.

Purification of staphylococcal alpha-hemolysin

Madoff, Morton A. (New England Center Hospital, Boston, Mass.) and Louis Weinstein. Purification of staphylococcal alpha-hemolysin. J. Bacteriol. 83:914-918. 1962. - Staphylococcal alpha-toxin has been purified by metal-ion precipitation, column chromatography, and continuous-flow paper electrophoresis. The resultant preparation is highly unstable. A single line is obtained on agar-gel diffusion analysis against staphylococcal antiserum. Two bands, both associated with hemolytic activity and migrating cathodally at pH 8.4, are obtained on starch-gel electrophoresis. Levels of lytic, dermonecrotic, and lethal toxin activity maintain a constant relationship in the crude and purified materials, suggesting the unity of these effects.

LIPOLYTIC ACTIVITIES OF STAPHYLOCOCCUS AUREUS. I. NATURE OF THE ENZYME PRODUCING FREE FATTY ACIDS FROM PLASMA LIPIDS

O'Leary, William M. (Cornell University Medical College, New York, N.Y.), and Julia T. Weld. Lipolytic activities of Staphylococcus aureus. I. Nature of the enzyme producing free fatty acids from plasma lipids. J. Bacteriol. 88:1356-1363. 1964.-The enzyme of Staphylococcus aureus, Guy strain, which is responsible for producing free fatty acids in human plasmas was purified approximately 225-fold from extracts of cultures in which the organism was grown. Purification procedures included ammonium sulfate precipitation, ethanol precipitation, gel filtration, and diethylaminoethyl-cellulose chromatography. Stability characteristics, pH and temperature optima, and substrate requirements were established. The principal plasma substrate is plasma lipoprotein, and the major reaction product is free octadecenoic acid. The ability of this compound to uncouple oxidative phosphorylation may be involved in the pathological effects of S. aureus at the molecular level.

PURIFICATION AND CHARACTERIZATION OF STAPHYLOCOAGULASE

Zolli, Zeno, Jr. (Michigan State University, East Lansing), and Charles L. San Clemente. Purification and characterization of staphylocoagulase. J. Bacteriol. 86:527-535. 1963.-Separation and extreme purification of coagulase from Staphylococcus aureus strain 70 was achieved by using three cycles of dialysis in ethanol-water mixtures under controlled conditions, followed by molecular sieving through a column of Sephadex G-200. By manipulation of five variables (pH, ionic strength, temperature, protein, and ethanol concentration), the final preparation showed an approximate 3700-fold increase in activity per mg of protein. The successfully isolated coagulase containing 15.0% nitrogen was characterized serologically and chemically. By use of agar diffusion techniques, one zone of precipitation was obtained with the highly purified material. Additional confirmation of purity was evidenced by the appearance of a single peak with cellulose acetate paper electrophoresis with a barbital buffer at pH 8.6. Progressive and eventual elimination of carbohydrate, deoxyribonuclease, lipase, and phosphatase was observed through the four stages of purification. Temperature studies showed that the stability of each fraction was inversely related to its purity.

Purification and properties of staphylocoagulase

Staphylocoagulase, an exoprotein of coagulase-positive Staphylococci, has been purified to a state in which only trace amounts of contaminating proteins are detectable. Aspartic acid was found as a single N-terminal amino acid in this preparation. The molecular weight is 61 000; the isoelectric point lies as pH 4.53. The amino acid composition was determined.

Activation of coagulase clotting by trypsin inhibitor

Egg white trypsin inhibitor activated coagulase clotting when added to a final concentration between 2 and 60 mg/ml. The greatest increase in clotting rate was observed in reaction mixtures containing the lowest concentrations of serum and plasma. Maximal activation was reached with 40 mg of trypsin inhibitor per ml when either serum or plasma was used as the source of coagulase-reacting factor (CRF). The increased rate of clotting is partly due to inhibition of plasmin. Freezing and thawing reduced plasma clotting inhibition. Soybean trypsin inhibitor also activated the coagulase reaction. The increased rate of clotting was observed with a coagulase preparation from organisms which produced plasminogen activators and with the culture supernatant fraction from organisms which did not activate plasminogen to plasmin. The tube test for coagulase could be made more sensitive for some strains of staphylococci by increasing the concentration of CRF (added as plasma or serum) by adding trypsin inhibitor, or both.

FIBRINOGEN MEDIA FOR STUDIES ON STAPHYLOCOCCI

Deneke, Anneliese (University of Wisconsin, Madison) and Hans Blobel . Fibrinogen media for studies on staphylococci. J. Bacteriol. 83: 533–537. 1962—Fibrinogen media were prepared simply by spreading rabbit plasma or a bovine fibrinogen solution over the surface of certain solidified agar media, thus eliminating the necessity of incorporation of fibrinogen into liquefied agar media at a critical temperature. With agar media composed of heart infusion broth, blood agar base, or Trypticase soy broth, distinct coagulase reactions were observed which corresponded closely to those obtained with the tube test.

A bovine fibrinogen solution, applied to the surface of some of the commonly used selective media for staphylococci, provided an additional and more specific test system for coagulase production of individual colonies, and consequently aided in the presumptive identification of pathogenic staphylococci.