VAL-1, a Novel Polysaccharide Lyase Encoded by Chlorovirus CVK2

Cell wall materials isolated from Chlorella cells were degraded by the polysaccharide-degrading enzyme vAL-1 encoded by chlorovirus CVK2. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analyses of the degradation products (oligosaccharides) revealed major oligosaccharides contain unsaturated GlcA at the reducing terminus, and a side chain attached at C2 or C3 of GlcA(C4?C5), which mainly consisted of Ara, GlcNAc and Gal. The results indicated that vAL-1 is a novel polysaccharide lyase, cleaving chains of beta- or alpha-1,4-linked GlcAs. The unique structures of Chlorella cell wall were also revealed. Studies on the complicated structures of naturally occurring polysaccharides will be greatly facilitated by using vAL-1 as a tool in structural analysis.