02440     2200217   4500001002100000005001500021035002000036007000300056008003900059082001500098084001500113100001900128245009100147250001800238260005200256300000600308650002800314700001800342700001300360520184900373INLIS00000000001905620240909113719  a0010-0924000135ta240909                |          | |    aARTVET1334  aARTVET13340 aSIMSON TARIGAN1 aKarakterisasi Aktivitas Enzimatik Neuraminidase Virus Influenza H5N1 /cSIMSON TARIGAN  aVol. 12 No. 2  aBalai Besar Penelitian Veteriner :bJITV,c2007  a7 4aEnzimatik Neuraminidase0 aRISA INDRIANI0 aDARMINTO  aOne of the two glycoproteins projected from the surface of the influenza virus is identified as neuraminidase. This enzyme
enables the virus to spread in the host, and therefore it plays vital roles in the viral pathogenicity. From the viewpoint of disease
control, neuraminidase is used as the target for the development of anti-flu drugs, and for the development of diagnostic test to
differentiate infected from vaccinated animals (DIVA). Since the roles of the enzyme are very important, information regarding
the characteristics and the procedure to measure its activity, which is the purpose of this study, is essential. The optimum
incubation time of the neuraminidase-substrate (fetuin) reaction and the optimum pH of the buffer were determined. The stability
of the enzyme against heating, supplementation or chelating of calcium ion, and ?-propiolactone treatment were analysed. This
study showed that neuraminidase from H5N1-influenza virus was, in regards to the characteristics investigated in this study, was
comparable to that from Clostridium perfringens. The optimum incubation time for the viral and Clostridial neuraminidases were
60 and 30 minutes, respectively; whereas, the optimum pH for both neuraminidase was 6-7. At pH 8, both neuraminidase were
inactive. Supplementation of calcium ion tended to increase activity but chelating of the cation did not have any observable
effects. Treatment with 0.2% ?-propiolactone for 6 hours reduced the activity, whereas heating at 60°C for 60 minutes abolished
all activity. Since inactivation by ?-propiolactone is partially only, neuraminidase assay could be performed safely in ordinary
laboratories using ?-propiolactone-treated-influenza virus, rather than the life virus. The thermolabile nature of the enzyme will
complicate any attempt to purify the enzyme.