Human IgG1 Lambda Isotype Control

The relationship between zinc sulfate turbidity test (ZTT) and thymol turbidity test (TTT), and IgG subclasses, especially IgG1 and IgG2, was studied. Serum colloidal reactions of specimens from patients with IgG-myeloma usually show abnormally high values in ZTT and low values in TTT. But in some cases, values in ZTT and TTT are both low, and in a few cases both values are abnormally high. In order to see the reason why IgG-myelomas are classified into these three groups according to serum colloidal reactions, IgG subclasses of monoclonal proteins (MPs) isolated by zone electrophoresis were determined by immunodiffusion with anti IgG-subclasses. Results revealed that IgG1-myeloma showed high ZTT and low TTT and IgG2-myeloma showed low ZTT and TTT. Only two out of our 29 cases with IgG-myeloma showed high ZTT and TTT. MP from one of them belonged to IgG1-kappa and that from the other to IgG2-lambda. We checked the relationship between turbidity tests and electrophoretic mobility of MP and also that between these tests and L-chains' type of MP, but did not find any relationship between them. These findings suggest that IgG1 innately reacts with ZTT but not with TTT, while IgG2 does not react with any of these tests. MP from cases showing high values in both ZTT and TTT may have a special idiotype.

Bovine herpesvirus 1 (BoHV-1) causes respiratory and genital diseases in cattle for which available vaccines do not confer adequate protection Since passive immunization with antibodies permits disease prevention, single-chain fragment variable (scFv), originating from a monoclonal bovine IgG1 antibody against BoHV-1, were constructed and expressed in Pichia pastoris in V-lambda-V-H orientation via a flexible seven-amino acid linker Similar to the intact IgG, the purified recombinant. scFv neutralized BoHV-1 in vitro and recognized vital antigens in BoHV-1 infected MDBK cells by immunofluorescence Homology modeling of the Fv predicts two distinct conformations for CDR3H Firstly, a long protruding CDR3H conformation where no disulfide linkage occurred between two "non-canonical" Cys residues resulted in a large binding cavity between V-lambda and V-H Secondly, a smaller potential antigen-binding cavity is predicted with a disulfide linkage between the two Cys residues of CDR3H creating a six-membered loop in the ascending polypeptide, which fitted into the space between V-lambda and V-H Despite such potential configurational diversity of the antigen-binding site, the electrostatic surface potentials that would interact with the BoHV-1 epitope are largely similar for both the topographies where salt-bridge type electrostatic interactions likely occur at the edges of the binding site Given that IgG1 antibody against BoHV-1 is clonally selected, it is likely that disulfide-stabilized broader and flatter surface topography is specifically generated to accommodate the predicted carbohydrate neutralizing B-epitope on BoHV-1 The specificity and neutralizing capacity for BoHV-1 of the scFv should make this bovine antibody fragment a useful diagnostic and potential therapeutic candidate for an important vital pathogen in cattle (C) 2009 Elsevier Ltd All rights reserved.