Protein and glycoprotein content of lymphocystis disease virus (LCDV).

The polypeptide and glycoprotein composition of eight strains of the fish-pathogenic lymphocystis disease virus (LCDV) isolated from gilt-head seabream (Sparus aurata), blackspot seabream (Pagellus bogaraveo), and sole (Solea senegalensis) were determined. The protein electrophoretic patterns of all LCDV isolates were quite similar regardless of the host fish, showing two major proteins (79.9 and 55.6 kDa) and a variable number of minor proteins. Three groups of LCDV isolates were distinguished according to the number and molecular masses of the minor proteins. Eight glycoproteins were detected inside viral particles of LCDV 2, LCDV 3 and LCDV 5 isolates, but only seven glycoproteins were found inside viral particles of LCDV 1, LCDV 4, LCDV 6, LCDV 7, and LCDV 11 isolates and the reference virus ATCC VR 342 by using five lectins. LCDV glycoproteins were mainly composed of mannose and sialic acid. These glycoproteins could be part of an external viral envelope probably derived from the host cell membrane.