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 part, the CH1 domain, and the hinge segment of the biologically relevant monoclonal mouse anti-alpha (2-8) polysialic acid antibody mAb735 is presented. The reduced and carboxymethylated H-chain was digested with trypsin and cyanogen bromide. For subfragmentation selected peptides were cleaved with thermolysin and endoproteinase Asp-N. The generated peptides were isolated by RP-HPLC and characterized by sequence analysis, 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 variable region of the H-chain belongs to the subgroup II. Sequence data from the constant region indicate that mAb735 represents the gamma 2a isotype.