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Biomedical subjects

G Ihler

Publications and source records attributed to G Ihler.

11 recordsLinked to original sources
PubMed1986

Plasmid expression vector using the lambda late promoter.

A plasmid expression vector called pQTE1 based on the late promoter, pR', and positive control gene Q of bacteriophage lambda has been constructed. This vector has unique cloning sites for placing exogenous DNA under control of pR'. Induction of expression of genes cloned into the pQTE1 plasmid leads to massive overproduction of the gene products. Also, transcription from the pR' promoter on pQTE1 appears to be insensitive to polarity effects.

Bacteriophage lambda↗
PubMed1978

Location of ribosome-binding sites on the tetracycline resistance transposon Tn10.

Eight ribosome-binding sites were located on the single-stranded Tn10 DNA loop which was formed after denaturation of lambda phage DNA containing the Tn10 transposon sequence. Ribosomes were bound only to the Tn10 loop contained on the R strand of lambda DNA but not to that on the L strand, suggesting that one of the two strands of Tn10 DNA is selectively transcribed. Six of the eight ribosome binding sites were located in one-half of the DNA loop. The maximum sizes of potential polypeptides were calculated for these genes to range between 9,500 and 84,000 daltons.

Binding Sites↗
PubMed1977

Visualization of ribosome--single-stranded DNA complexes in the electron microscope.

A procedure is described which allows ribosomes bound to single-stranded DNA to be visualized in the electron microscope. The number of bound ribosomes may be determined and the position of the bound ribosomes may be readily measured along the DNA. The distribution of ribosomes bound to separated l and r strands of lambda DNA was shown to conform to the pattern predicted for binding at specific sites. The procedure should allow mapping of ribosome binding sites for the determination of genetic maps and may also be useful for studying translational control and relative binding affinities for ribosomes.

Binding Sites↗
PubMed1977

Effect of glutaraldehyde treatment on enzyme-loaded erythrocytes.

In principle, enzyme-loaded erythrocytes can be used as a vehicle for enzyme replacement therapy in lysosomal storage diseases. Glutaraldehyde treatment renders these erythrocytes more resistant to lysis without inactivating the enzymes that have been entrapped inside them. Glutaraldehyde treatment does not prevent ingestion of enzyme-loaded erythrocytes by macrophages in vitro so that these cells can be used to deliver enzymes to lysosomes. In vivo, the glutaraldehyde-treated cells are quickly removed from the circulation by the spleen or liver. The degree of glutaraldehyde treatment allows the erythrocytes to be targeted either to the spleen (low glutaraldehyde concentrations) or to the liver (higher glutaraldehyde concentrations).

Aldehydes↗
PubMed1977

A dialysis procedure for loading erythrocytes with enzymes and lipids.

A dialysis procedure for hypotonic hemolysis has been developed in which erythrocytes can be loaded with water-soluble enzymes, detergent-solubilized enzymes (glucocerebrosidase) and detergent-dispersed glycolipid (glucocerebroside). The procedure allows approx. 40-50% of the added enzyme or glycolipid to be encapsulated. The final intracellular concentration of enzyme or glycolipid is about to the extracellular concentration. The loaded cells can be ingested by macrophage in vitro and the glucocerebroside partially degraded by lysosomal glucocerebrosidase. The use of this procedure for the investogation of Gaucher's disease is discussed.

Cerebrosides↗
PubMed1976

Isolation and properties of an inhibitor of Escherichia coli RNA polymerase.

An inhibitor of the Escherichia coli RNA polymerase has been isolated from E. coli and has been partially characterized. The inhibitor, a polypeptide of molecular weight 70000, acts to shut off RNA synthesis at about the time that the first round of RNA synthesis is over, preventing any further RNA synthesis. The inhibitor apparently does not recognize specific termination sequences in the DNA template, since it works equally well with double-stranded DNA, single-stranded DNA and poly[d(A-T)] as templates for RNA synthesis, and because the RNA molecules synthesized from T7 DNA appear to be terminated at the same site either in the presence or absence of the inhibitor. Several experiments indirectly indicate that the inhibitor may reversibly bind to the RNA polymerase at the termination step, in a ratio of approximately one inhibitor molecule per polymerase molecule.

Bacterial Proteins↗
PubMed1975

Enzymatic degradation of uric acid by uricase-loaded human erythrocytes.

Erythrocytes containing pig liver uricase have been prepared by hypotonic hemolysis in the presence of the enzyme. Uricase is shown to be active within the erythrocytes and to degrade uric acid as rapidly as it enters the cells when high intracellular enzyme concentrations are employed. The kinetics and characteristics of uric acid entry are shown to be the same for hemolysed and normal erythrocytes. At physiological concentrations of uric acid, loaded erythrocytes can degrade a maximum of about 21 mumol uric acid/liter erythrocytes per min. The possible application of enzyme-loaded erythrocytes to medicine is discussed.

Biological Transport↗