TITLE:
Characterization of Chitotriosidase Enzyme Activity in the Serum of the American Alligator (Alligator mississippiensis)
AUTHORS:
Kenneth Kidder, Rodolfo Falconi, Mark Merchant
KEYWORDS:
Antifungal, Crocodilian, Crocodylian, Innate Immunity
JOURNAL NAME:
Advances in Biological Chemistry,
Vol.8 No.5,
October
10,
2018
ABSTRACT: Chitotriosidase (ChT) is an endoglucosaminidase
enzyme that cleaves chitinous substrates and has been strongly associated with
innate immune activity and the ability to identify non-selftissues. This enzyme
activity was detected and characterized the serum from the American alligator (Alligator mississippiensis) using a
fluorometric probe. Alligator serum exhibited volume-dependent activity, with
activity (2.1 ± 0.3 μmol/min) observed at dilutions as low as a 1:150, and
maximum activity (5.2 ± 0.6 μmol/min) measured at a dilution of 1:30. Alligator
serum ChT showed linear activity for approximately 20 min, at which time
activity decreased exponentially, presumably due to the depletion of substrate.
In addition, the ChT activity in alligator serum was temperature-dependent with
low activity at 5°C, a sharp increase from 10°C - 30°C,
and maximal activity from 30°C - 40°C. The activity was inhibited in the
presence of water-soluble chitin, but not mannan, indicating the specificity of
the enzyme. The presence of ChT in alligator serum is likely to be partially
responsible for the potent innate immune system of these crocodylians, and
particularly antifungal activities.