KARL MEYER 



sidic linkages in hyaluronic acid, as measured by the increase in re- 

 ducing power; (b) the decrease in viscosity of hyaluronate-containing 

 solutions; and (c) the decrease of the protein-precipitating power of 

 hyaluronate after enzymic depolymerization. The last method in a 

 modification of that of Kass and Seastone (16) has proved most con- 

 venient and accurate. 



Group A and C hemolytic streptococci are the only micro- 

 organisms in which hyaluronic acid has been demonstrated. It 

 apparently is formed only when these organisms possess a mucoid 

 capsule. Seastone has brought forward good evidence for the parallel- 

 ism of capsule formation, hyaluronic acid production, and the invasive- 

 ness of the organisms. Incubation with hyaluronidase causes the 

 disappearance of the capsule. Furthermore, intraperitoneal injection 

 of hyaluronidase was shown to protect mice against fatal doses of 

 intraperitoneally injected group A and G streptococci (16). 



While some strains produce hyaluronic acid, other strains be- 

 longing to group A, C, and G produce hyaluronidase. Hyaluronic 

 acid and hyaluronidase production do not seem to occur simultane- 

 ously. In a recent study (7) involving 308 strains of group A strepto- 

 cocci, hyaluronidase production was found only in strains belonging 

 to type 4 and 22. The group A strain used mosdy in our studies also 

 belonged to type 4. 



When hyaluronidase activity was determined chemically with 

 culture filtrates or fractions isolated from streptococci, a peculiar 

 behavior was noted, in that the activity measured viscometrically or 

 by reduction stopped after an initial reaction. In fact in many tests 

 with hyaluronidase-producing strains no enzyme could be demon- 

 strated in the majority of tests. The explanation for the abnormalities 

 may be found in an enzymic destruction of hyaluronidase by strepto- 

 coccus extracts. 



For the concentration and purification of hyaluronidase, bull or 

 ram testis is the most convenient source. Thus, far, the enzyme has 

 never been obtained as a pure protein. Beside inert proteins, testicular 

 preparations contain an enzyme hydrolyzing chondroitin sulfate into 

 disaccharide units containing sulfate (27). The hyaluronidase activity 

 in most preparations runs parallel with that of the enzyme which 

 sphts chondroitin sulfate, including samples purified in the final step 

 by electrophoretic separation. The two enzymes are, however, sepa- 



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