Arthrobacter ureafaciens sialidase

Seven different bacterial sialidases, including six commercially available sialidases from Arthrobacter ureafaciens, Clostridium perfingens. Streptococcus sp. IID, Vibrio cholera. Salmonella typhimurium, and Streptococcus pneumoniae, as well as PmSTl which also possesses sialidase activity (20), were used as model systems to test the application of the sialoside library and the 96-well plate based high-throughput colorimetric screening method. 

Ajisaka et al. examined different sialidase somces and found that Newcastle disease virus (NDV) sialidase afforded predominantly the a-2,3 regioisomers, while Arthrobacter ureafaciens and Clostridium perfringens sialidases, in addition to the Vibrio cholerae sialidase examined by Thiem, favored the a-2,6-linked products [53]. Unfortunately, the reaction yields did not improve for the new enzymes, varying from 0.8% to 3.6% isolated yield. In the case of NDV sialidase, the high selectivity for a-2,3-sialosides stemmed from a large a-2,6/a-2,3 hydrolysis ratio. Hydrolysis of the a-2,6 products was found to be 28 times faster than the a-2,3 isomers. Inter-... 

The use of sialidases for the preparation of acylneuraminic acids has several advantages over the relatively destructive acid hydrolysis techniques. The hydrolysis is carried out under milder conditions of temperature and pH. Low temperatures (0-4 °C) can be employed and even on prolonged incubation (24-48 h) the destruction of released acylneuraminic acids is usually below 5%. The sialic acids are released into aqueous solution at pH 5-6, where they are stable for the duration of the incubation. The use of sialidases is widespread, and several bacterial preparations are available in partially purified form well suited for the experiments outlined here. The most widely available sialidases are those from Vibrio cholerae, Clostridium perfringens and Arthrobacter ureafaciens, and these have sufficiently high specific activities to be used in preparative work. Details of the properties and specificities of these and other sialidases are given in chapter I and in reviews by Drzeniek (1972, 1973) and Corfield et al. (1981). 

Fig. 5. The effect of naturally occurring N-acyl substitution on sialidase activity. A time curve of Neu5Acyl release from sialyl a(2-3)-lactose by Arthrobacter ureafaciens sialidase (A A, 1 mU) and from sialyl a(2-6)-N-acetylgalactosamine by Clostridium perfringens enzyme (O 3.2 mU). The substrates contain either N-acetyl- (O A) or N-glycolyl- ( , A) sialic acids at 1 mM final concentration.

Saito, M., Sugano, K., and Nagai, Y, 1979, Action of Arthrobacter ureafaciens sialidase on sialoglycolipid substrates, J. Biol. Chem. 254 7845-7854. 

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