Table 2.

Characteristics of some insect chitinases

MsCHT-1BmCHT-1AaCHT-1
Organism Manduca Bombyx Aedes
sexta mori aegypti
Accession no.A56596AAB47538AAB81849
Molecular mass (kDa)
   Deduced from cDNA62.2063.3964.27
   Zymogenic forms*119215
   Active forms50, 62, 75, 9754, 65, 8833, 40
pI5.325.154.83
PEST sites404—437417—440394—408
474—508471—499413—436
451—471
Total number of N-glycosylation sites332
Total number of O-glycosylation sites242325
  • Prediction of putative PEST sites and N- and O-glycosylation sites was performed with the programs PESTfind, PROSCAN and NetOGlyc 2.0, respectively (Rogers et al., 1986; Bairoch et al., 1997; Hansen et al., 1997).

    pI, isoelectric point.

  • * Putative zymogenic forms were suggested based on their immunoreactivity with anti-chitinase antibodies after SDS-PAGE and western blots (Koga et al., 1989, 1992)