The inhibitory activities of several allosamidin derivatives on two
family 18 chitinases, an insect enzyme from the epithelial cell line
from Chironomus tentans, and a bacterial enzyme, chitinase A from
Serratia marcescens, were evaluated. The following structural
requirements are necessary for inhibition of the Chironomus enzyme:
1. One N-acetylallosamine residue can be omitted without impairment of
enzyme inhibition.
2. At least one N-acetylallosamine sugar must be present.
3. Glucosamine can replace the allosamine moiety without a negative
effect on the inhibitory activity.
4. The spatial arrangement of the allosamizoline moiety is important for
inhibition.
5. If one sugar is omitted and the arrangement of the cyclitol residue
is changed, the inhibitory effect is diminished further.
For purified chitinase A from Serratia marcescens the arrangement of the
aglycone moiety is equally important, but recognition of the sugar is
different:
1. Omission of one allosamine residue decreases the inhibitory activity
considerably.
2. Inhibition is improved if the remaining N-acetylallosamine is
replaced by the epimer N-acetylglucosamine.
Only endochitinase activity is affected, since chitin formation (up to
10(-4) M) and N-acetylglucosaminidase activity (up to 10(-3) M) are not
impaired, at least in Chironomus cells. (C) 1998 SCI
