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Biomedical subjects

W Konigsberg

Publications and source records attributed to W Konigsberg.

At least 37 records · Page 2Linked to original sources
PubMed1981

Structure of filamentous bacteriophage: isolation, characterization, and localization of the minor coat proteins and orientation of the DNA.

The minor coat proteins of the filamentous bacteriophage fl and fd have been isolated and characterized. The phage have approximately 5 copies each of the A protein (product of gene III) and the D protein (product of gene VI). The phage also contains about 10 copies of the C protein. Preliminary evidence suggests that the "C protein" may actually be a mixture of proteins, the major component of which is the product of gene IX. The D protein is located near or at the A protein end of the phage, and the C protein is located in a region near or at the other end. The DNA appears to be oriented iun the virion such that the DNA which specifies the intergenic region is located close to the C protein end of the phage and that which codes for the gene III protein is located near the A and D protein end.

Binding Sites↗
PubMed1980

Isolation and characterization of the C and D proteins coded by gene IX and gene VI in the filamentous bacteriophage fl and fd.

The C and D proteins from bacteriophage fd and fl have been purified and characterized. Since the DNA sequence is known, the amino acid composition of these purified proteins indicated that they are coded for by the phage, the C protein being the product of Gene IX and the D protein specified by Gene VI. The molecular weights of the C and D proteins were calculated from the DNA sequences to be 3,650 and 12,350, respectively. These values are close to the molecular weights observed after polyacrylamide gel electrophoresis of the proteins in sodium dodecyl sulfate. Since the C and D proteins can be selectively labeled with radioactive cysteine and arginine, it was possible to estimate the number of the C and D protein molecules relative to the number of A protein molecules which had been accurately determined in previous studies. Based on these results, the average phage particle contains 5 A, 5 D, and 10 C protein molecules.

Amino Acids↗
PubMed1980

Sequences of the recA gene and protein.

We have determined the nucleotide sequence of the recA gene of Escherichia coli; this permits the formulation of the primary structure for the recA protein. This structure is consistent with the amino acid composition of the tryptic peptides obtained from the recA protein. The coding region of the recA gene has 1059 base pairs, which specify 352 amino acids. The recA protein has alanine and phenylalanine as its NH2- and COOH-terminal amino acids, respectively, and has the following amino acid composition: Cys3 Asp20 Asn15 Met9 Thr17 Ser20 Glu30 Gln13 Pro10 Gly35 Ala38 Val22 Ile27 Leu31 Tyr7 Phe10 His2Lys27 Trp2 Arg14. Of the three cysteine residues, only two can be alkylated under reducing and denaturing conditions. The molecular weight of the recA polypeptide is 37,842.

Amino Acid Sequence↗
PubMed1980

Mutation in the structural gene for seryl-transfer ribonucleic acid synthetase of Escherichia coli which affects formation of its gene product at high temperature.

The rate of formation of seryl-transfer ribonucleic acid (tRNA) synthetase activity was temperature dependent in a temperature-sensitive mutant of Escherichia coli (K28) with an altered seryl-tRNA synthetase structural gene and in a class of spontaneous revertants derived from it. These revertants, which were selected by their ability to grow at 45 degrees C, had high levels of the thermolabile enzyme. The rate of formation of seryl-tRNA synthetase activity in the mutant and in the revertants fell from 100% to near zero with a 4 degrees C temperature range from 40 to 44 degrees C. The temperature-dependent rate of formation of seryl-tRNA synthetase activity was reversible. Dropping the temperature from 44 to 37 degrees C resulted, after a 2- to 3-min delay, in a resumption of the initial rate of formation of enzyme activity. The results could not be accounted for by in vivo or in vitro degradation of the active enzyme. Addition of rifampin just before the temperature shift down from 44 to 37 degrees C inhibited the appearance of seryl-tRNA synthetase activity at the lower temperature. Explanations which might account for these phenomena are proposed.

Amino Acyl-tRNA Synthetases↗
PubMed1978

Structural changes in the T4 gene 32 protein induced by DNA polynucleotides.

Alterations in the structure of the DNA-binding protein specified by gene 32 of bacteriophage T4 have been detected using partial trypsin digestion as a conformational probe. Limited tryptic hydrolysis of the gene 32 protein removes a fragment ("B" region), of 21 amino acids from the NH2 terminus and a 6,200-dalton fragment ("A" region) from the COOH terminus. Poly(dT), poly(dC), and single-stranded DNA increase the rate of tryptic hydrolysis of the "A" region but decrease the rate of tryptic hydrolysis of the "B" region. Oligonucleotides, which are too short to permit cooperative binding of the gene 32 protein, do not alter the rate of tryptic hydrolysis of either the "A" or "B" regions. A model which accounts for these findings requires that the "B" region be involved in gene 32 protein:gene 32 protein interactions when the gene 32 protein: DNA complex is formed. As a consequence of the gene 32 protein:DNA interaction, the "A" region should be able to participate more effectively in vivo and in vitro with other proteins involved in T4 DNA metabolism.

Amino Acid Sequence↗
PubMed1977

Amino acid sequence of the VH region of a human myeloma immunoglobulin (IgG New).

The amino acid sequence of the heavy-chain variable region of the human immunoglobulin. New has been determined. Since the amino terminus of the heavy chain was blocked, the sequence of residues 1-69 was established by digesting the appropriate CNBr fragment separately with trypsin, chymotrypsin, and thermolysin and sequencing the resulting peptides. The region from residues 70 to 120 was present in another CNBr fragment which was submitted directly to automatic Edman degradation. The result of this experiment extended the sequence to residue 100. The primary structure of the remaining portion of the VH region was determined by automatic Edman degradation of a lysine-blocked tryptic peptide derived from this region which included residues 98-214. The sequence of the VH region of New corresponds most closely to VH sequences of proteins in the VH II subgroup. This primary structure makes it possible to construct a model from the high-resolution electron-density map of protein New.

Amino Acid Sequence↗
PubMed1975

The activation of coagulation factor X. Identity of cleavage sites in the alternative activation pathways and characterization of the COOH-terminal peptide.

Bovine Factor X can be activated by two alternative pathways. The first, favored at high concentrations of the complex of tissue factor and Factor VII, is initiated by the action of Factor VII on Factor X to cleave an activation peptide from the NH2 terminus of the heavy chain, to produce alpha-Xa. This is then converted autocatalytically to another form of Factor Xa, beta-Xa, by the loss of a 17-residue glycopeptide from the COOH terminus of the heavy chain, in a lipid-dependent reaction. The alternative pathway, favored at lower activator concentrations, is initiated by the action of Factor Xa on Factor X, in the presence of lipid, to release the same COOH-terminal peptide as is produced in the conversion of alpha-Xa to beta-Xa. The intermediate produced by the loss of this peptide from Factor X,I1, can be activated directly to beta-Xa by the tissue factor-Factor VII complex, with the loss of the same NH2-terminal peptide as is produced in the conversion of Factor X to alpha-Xa. The autocatalytic activation of Factor X by Factor Xa described previously occurs to a marked extent only at very low activator concentrations, and has been shown to proceed largely by the loss of the normal NH2-terminal peptide from the heavy chain of I1-Initial experiments show that neither peptide affects the rate of coagulation by either the extrinsic or intrinsic pathways. The amino acid sequences have been determined on both sides of the peptide cleavages, and it has been shown that the cleavage sites are the same, regardless of the pathway of activation. The amino acid sequence and carbohydrate composition of the COOH-terminal peptide have been determined. The carbohydrate moiety is attached via an O-glycosidic linkage at a threonine residue, and contains galactosamine but no glucosamine.

Amino Acid Sequence↗
PubMed1975

Photo-incuced cross-linkage of gene-5 protein and bacteriophage fd DNA+.

The gene 5 protein, coded for by the bacteriophage fd, forms a complex with single stranded fd-DNA such that one gene 5 protein monomer interacts with four bases. Exposure of this complex to ultraviolet light results in the formation of covalent bonds between 25-30% of the gene 5 protein monomers which are bound to the DNA. In contrast, when the intact fd virion, which is a complex of coat protein and DNA, was exposed to ultraviolet irradiation, no detectable protein DNA cross-links were found.

Bacterial Proteins↗