We used a library of 31 monoclonal and six polyclonal antibodies to compare the structures of the two classes of cytoplasmic myosin isozymes isolated from Acanthamoeba: myosin-I, a 150,000-mol-wt, globular molecule; and myosin-II, a 400,000-mol-wt molecule with two heads and a 90-nm tail. This analysis confirms that myosin-I and -II are unique gene products and provides the first evidence that ...

BACKGROUND Antibody fragments selected from large combinatorial libraries have numerous applications in diagnosis and therapy. Most existing antibody repertoires are derived from human immunoglobulin genes. Genes from other species can, however, also be used. Because of the way in which gene conversion introduces diversity, the naïve antibody repertoire of the chicken can easily be accessed usi...

Sharks and other cartilaginous fish are the phylogenetically oldest living organisms that rely on antibodies as part of their adaptive immune system. They produce the immunoglobulin new antigen receptor (IgNAR), a homodimeric heavy chain-only antibody, as a major part of their humoral adaptive immune response. Here, we report the atomic resolution structure of the IgNAR constant domains and a s...

Changes in the expression of heavy chains of myosin during development determine the functional characteristics of striated muscles. The distribution of heavy-chain isoforms of smooth-muscle myosin was determined in the airways of adult and infant humans to see whether it might underlie the hyperreactivity of human airways. The protein bands corresponding to myosin were separated using SDS/poly...

Factor IXa was shown to inactivate both factor Vlll and factor Vllla in a phospholipid-dependent reaction that could be blocked by an antifactor IX antibody. Factor IXa-catalyzed inactivation correlated with proteolytic cleavages within the A1 subunit of factor Vllla and within the heavy chain (contiguous AI-A2-6 domains) of factor VIII. Furthermore, a relatively slow conversion of factor Vlll ...

BACKGROUND An anti-CD146 monoclonal antibody, AA98, has been identified as an inhibitor of tumor angiogenesis. To overcome the inherent immunogenicity of murine antibody as well as to facilitate immunotoxin construction, a single chain AA98 V(H)/L with three-domain fragments was constructed and expressed in mammalian cells. MATERIALS AND METHODS The genes of the AA98 heavy chain variable regi...

Cells of the MPC-11 mouse myeloma cell line, which produces an IgG2b immunoglobulin, were subjected to mutagenesis with Melphalan or with ICR-191, after which they were cloned in soft agar. Approximately 0.5 percent of the clones produced altered heavy chains that: (i) were the same size as or larger than the parent; (ii) no longer recognized by antibody specific for the parent gamma2b subclass...

High-rate antibody-forming cells and immunological memory cells can be selectively retained if filtered through a column coated with relevant antigen. This trapping can be blocked if the cells are incubated with an anti-immunoglobulin serum prior to column passage. A similar blocking is not observed when cells are treated with an anti-lymphocyte serum, thereby excluding the possibility that any...

Secretory IgA (sIgA) is a crucial antibody in host defense at mucosal surfaces. It is a promising antibody isotype in a variety of therapeutic settings such as passive vaccination and treatment of inflammatory disorders. However, heterologous production of this heteromultimeric protein complex is still suboptimal. The challenge is the coordinate expression of the four required polypeptides; the...