234 IMM UNO-CATALYSIS 



on the polysaccharide of vitreous humor. They called this enzyme 

 mucinase, and considered it identical with the spreading factor. 



In the meantime, Meyer, et at. ( 1940a and b), described the nature 

 of the pneumococcal enzyme hydrolyzing hyaluronic acids from various 

 sources. This enzyme v\^as also prepared from Group A hemolytic strep- 

 tococci, though the activity was somewhat less than that of pneumo- 

 cocci. The latter acting on hyaluronic acid caused a fall of viscosity, and 

 its hydrolysis into N-acetylglucosamine and glucuronic acid. They called 

 this enzyme "hyaluronidase" (1940b). The action of pneumococcal 

 enzyme on the hyaluronic acids from various animal, bacterial and 

 tumour sources was specific. It acted also on a synthetic hyaluronic 

 acid trisulfuric ester. On the other hand, an enzyme preparation from 

 CI. welchii reacted less specifically. It hydrolyzed starch, glycogen, 

 neutral polysaccharide, chondroitin-sulfuric acid, and mucoitin-sulfuric 

 acid from pig gastric mucosa, in addition to hydrolyzing natural 

 hyaluronic acid. Evidently it represented a mixture of enzymes. They 

 also stated that the pneumococcal enzyme acting on hyaluronic acid is 

 not the same as that responsible for the lysis of pneumococci. 



About the same time. Chain and Duthie (1940) published their sec- 

 ond paper in which they dropped the name mucinase and adopted 

 "hyaluronidase." In a paper, appearing some months before that of 

 the above authors, Robertson, Ropes and Bauer (1940) used the term 

 mucinase for the mucolytic enzyme they isolated from CI. ■perfringens. 

 Chain and Duthie (1940) measured the activity of hyaluronidase by 

 the amount of reducing substances and N-acetylglucosamine it lib- 

 erated, and the rate of the fall of the viscosity of hyaluronic acid. The 

 enzymatically active solution was likewise tested for its spreading 

 property. In a series of nine animals, they found that in every case a 

 clearly recognizable difference between the area of spread was pro- 

 duced by 0.25 and 0.1 units of the standard testis preparation. Com- 

 paring the unit activity of the spreading factor of standard testis 

 extract, leech extract (Claude, 1937, 1940), copperhead venom, black 

 tiger venom, bee sting, CI. welchii toxin and pneumococcus culture 

 with the hyaluronidase activity, good agreement was obtained with 

 testis, leech and venom enzyme. With bacteria and snake venom 

 hyaluronidase, somewhat bigger spreads were obtained than were ex- 

 pected from their hyaluronidase content. The reason for this difference, 

 they believed, was most probably due to the oedema caused by these 

 fluids. 



