ABSTRACT
Antibodies were raised against a synthetic peptide corresponding to 14 amino acid residues at the COOH-terminus of a protein deduced from the human c-erbB-2 nucleotide sequence. These antibodies immunoprecipitated a 185-kilodalton glycoprotein from MKN-7 adenocarcinoma cells. Incubation of the immunoprecipitates with (gamma-32P)ATP resulted in the phosphorylation of this protein on tyrosine residues. These results indicate that the human c-erbB-2 gene product is the 185-kilodalton glycoprotein that is associated with tyrosine kinase activity. Although the c-erbB-2 protein was predicted to encode a protein very similar to epidermal growth factor (EGF) receptor, EGF did not stimulate this kinase activity either in vivo or in vitro.
Subject(s)
Genes , Glycoproteins/metabolism , Protein-Tyrosine Kinases/metabolism , Amino Acid Sequence , Epidermal Growth Factor/metabolism , ErbB Receptors , Glycoproteins/genetics , Glycoproteins/isolation & purification , HeLa Cells/metabolism , Humans , Molecular Weight , Oncogenes , Phosphorylation , Receptors, Cell Surface/metabolismABSTRACT
An eleventh case of heavy (Hgamma1) chain disease (Yok), surviving for more than 10 years and still living showed clinical and pathological findings similar to cases described in the past. The patient was given only glucocorticosteroids, ACTH, antibiotics and gamma globulin, as specific drugs. Precipitation arcs besides the major ones formed by albumin and Fc fragment were disclosed by immunoelectrophoresis. The existence of these minor components were confirmed with antigen-antibody crossed electrophoresis and Sephadex G-200 gel filtration. They did not form precipitation arcs with the other antigens available and they appeared in the same fractions of IgG on gel filtration suggesting their having higher molecular weight than the major ones. In addition to these findings, the clinical course of the patient is described.
Subject(s)
Heavy Chain Disease , Adult , Blood Proteins/analysis , Female , Heavy Chain Disease/metabolism , Humans , Immunoglobulin Fc Fragments/analysis , Serum Albumin/analysisABSTRACT
An abnormal protein with similar antigenic properties to Fc fragments of IgG, was found in the serum and urine of an eleventh case of heavy (Hgamma1) chain disease (Yok). This protein was purified with ammonium sulfate precipitation and by column chromatography of DEAE cellulose, CM cellulose and Sephadex G-200. The purity of the protein obtained was 98.5%. It was crystallized easily, forming thin hexagonal plates of various sizes. The chemical compositions and physical properties of the protein including viscosity, partial specific volume, diffusion constant, sedimentation constant, frictional ratio, extinction coefficient and iso-ionic point are reported.
Subject(s)
Heavy Chain Disease/metabolism , Immunoglobulin Fc Fragments/isolation & purification , Adult , Amino Acids/analysis , Carbohydrates/analysis , Electrophoresis, Paper , Female , Humans , Immunoelectrophoresis , Molecular Weight , ViscosityABSTRACT
In vitro quantitative biosynthetic studies were carried out on bone marrow cells obtained from an eleventh case with gamma heavy chain disease. The findings indicate that neither cytoplasmic nor extracellular degradation was responsible for the presence of the gamma heavy chain fragment in serum. The absence of a covalent-bound light chain was also confirmed.
