Immunoelectron Microscopy of Hemocyanin from the Keyhole Limpet (Megathura crenulata): A Parallel Subunit Model

Abstract Immunoelectron microscopy has been performed using negatively stained immune complexes of keyhole limpet hemocyanin (KLH) subunit 2 di- and multidecamers with domain-specific monoclonal antibodies. One antibody (KLH2 a macr 1) links the hemocyanin molecules in a side-to-side pattern, whereas the other antibody (KLH2 fg macr 1) links the molecules end-to-end. From existing knowledge of the domain sequence of KLH subunit 2, these data provide support for a parallel arrangement of subunits within each decamer. Ten N-terminal a macr: domains are then present at the noncollar region of each decamer with 10 C-terminal g macr domains at the collar region. The immunonegative staining data …