ABSTRACT
The fragment of the structural gene coding for the Fc-receptor of Streptococcus Valente (G group) has been cloned. The resulting recombinant plasmid pPGSV1 contains the O, kb HindIII fragment of streptococcal chromosomal DNA inserted into the vector plasmid pUC19 and determines the expression of the 31 kD protein in Escherichia coli cells. The protein binds the immunoglobulins of human, rabbit, guinea pig origin, but in contrast to the G protein of another G group streptococcus it is nonreactive with mouse, pig and sheep IgG.
Subject(s)
Bacterial Proteins/genetics , Immunoglobulin G/metabolism , Receptors, Fc/metabolism , Streptococcus/metabolism , Chromosomes, Bacterial , Cloning, Molecular , Escherichia coli/genetics , Humans , Immunohistochemistry , Plasmids , Recombinant Proteins/genetics , Species Specificity , Streptococcus/immunology , Substrate SpecificityABSTRACT
Large peptide fragments of human leucocyte interferon-alpha 2 (INF-alpha 2) were obtained by limited proteolysis with trypsin, pepsin, thermolysine and Bacillus amyloliquefaciens intracellular serine proteinase. The ability of the fragments to bind murine monoclonal antibodies NK2 raised against INF-alpha 2 was studied by the immunoblotting technique. The region of sequence 110-149 is the most sensitive to proteolytic attack, being probably exposed on the surface of the INF-alpha 2 molecule. INF-alpha 2 fragments 1-139, 1-147, 1-149 are capable of binding antibodies, whereas fragments 1-109 and 1-112 do not bind antibodies NK2. A comparison of the primary structure of human leucocyte and murine leucocyte INF families in the region of sequence 110-139 and an analysis of the ability of human INF differing in amino acid sequences to bind antibodies NK2 demonstrated that the antigenic determinant for antibodies NK2 is the sequence Glu114-Asp115-Ser116-Ile117 of the INF-alpha 2 molecule.
Subject(s)
Antibodies, Monoclonal/immunology , Epitopes/analysis , Interferon Type I/analysis , Peptide Fragments/analysis , Amino Acid Sequence , Animals , Binding Sites, Antibody , Electrophoresis, Polyacrylamide Gel , Humans , Hydrolysis , In Vitro Techniques , Interferon Type I/immunology , Mice , Peptide Fragments/immunology , Peptide HydrolasesABSTRACT
The kinetics of accumulation of poly(A+)mRNA in polyribosomes and the ratio: poly(A+)mRNA/(poly A-)mRNA were studied in regenerating mouse liver. It has been found, that the ratio: (poly A+)mRNA/(poly A-)mRNA was associated with the function of the cells: (poly A+)mRNA fraction has been decreased to 7% at 7 hours after partial hepatectomy and then reached the original value (25%) at 30-40 hours. The kinetics of accumulation of (poly A+)mRNA in polyribosomes during the transition from resting to growing state has revealed that both the lifetime and the presumable time of processing of the mRNAs of free and membranebound polyribosomes were decreased as compared to resting liver cells.