Characteristics of a Chondroitin AC Lyase Produced by Cytophaga columnaris

Abstract

Cytophaga columnaris produces, in culture, an enzyme that degrades chondroitin sulfates A and C and hyaluronic acid, the complex polysaccharides of connective tissue. This study is the first to demonstrate production of such a tissue-degrading enzyme by this fish pathogen. Partial characterization of the enzyme has shown it to be of the chondroitin AC lyase type that has been described for some other bacteria. No relations were found between the host origin, geographic distribution, and amount of enzyme produced by the different isolates. The enzyme is constitutive, is released into the medium as it is produced, has a molecular weight estimated at 42,600, and has an optimum pH of 6.0. Kinetic studies indicate enzyme specificities in the order chondroitin sulfate A > chondroitin sulfate C > hyaluronic acid. The enzyme showed little or no reaction with chondroitin sulfate B and none with heparin, pectic acid, arabinogalactan, gum guar, or gum acacia. The enzyme was produced by all 16 C. columnaris isolates tested in the study but by none of the 13 isolates of non-columnaris, yellow-pigmented bacteria of aquatic origin.