PRIMARY STRUCTURE OF THE MURINE MONOCLONAL IGG2A ANTIBODY MAB735 AGAINST ALPHA(2-8) POLYSIALIC ACID .2. AMINO-ACID-SEQUENCE OF THE HEAVY (H-)CHAIN FD' REGION

The complete amino acid sequence of the Fd' region including the VH pa rt, the CH1 domain, and the hinge segment of the biologically relevant monoclonal mouse anti-alpha(2-8) polysialic acid antibody mAb735 is p resented. The reduced and carboxymethylated H-chain was digested with trypsin and cyanogen bromide. For subfragmentation selected peptides w ere cleaved with thermolysin and endoproteinase Asp-N. The generated p eptides were isolated by RP-HPLC and characterized by sequence analysi s, plasma desorption mass spectrometry (PDMS), and amino acid analysis . The N-terminal sequence was determined after enzymatic deprotection with pyroglutamate aminopeptidase. According to Kabat et al. the varia ble region of the H-chain belongs to the subgroup II. Sequence data fr om the constant region indicate that mAb735 represents the gamma2a iso type.