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R H Haschke

Publications and source records attributed to R H Haschke.

34 records · Page 2Linked to original sources
PubMed1980

Preparation and retrograde axonal transport of an antiviral drug/horseradish peroxidase conjugate.

Recurrent Herpes simplex virus infections of the cornea are currently treated with antiviral drugs administered locally during periods of active infection. We have examined the feasibility of an alternate approach to treating recurrent infection, that of delivering an antiviral drug by axonal transport to cell somata in the trigeminal ganglion where the latent virus is thought to reside. We have coupled an antiviral drug to horseradish peroxidase (HRP), a protein which is readily transported retrogradely in corneal sensory axons to ganglion cell somata in the trigeminal ganglion. The antiviral drug 5-iodo-5'-amino-2',5'-dideoxyuridine (AIDU) was synthesized with 125I and coupled to horseradish peroxidase by Schiff base formation between the 5' amino group and aldehydes generated on the carbohydrate of the HRP following short periodate oxidation. The useful ratio of AIDU:HRP was 2-9; higher ratios resulted in an insoluble product. Sodium dodecylsulfate (SDS) acrylamide gel electrophoresis of the drug-protein conjugate revealed considerable aggregation and the isoelectric point of HRP was changed from 8.1 to 4.4-5.8 following the coupling procedure. Despite evidence that the protein conformation was considerably altered, the specific enzymatic activity of the final product was 58% of native HRP and the drug-protein conjugate was still strongly transported retrogradely. Retrograde transport of this conjugate was demonstrated by autoraiography of the trigeminal ganglion neurons 24 h after corneal injection of the [125I]AIDU/HRP.

Animals↗
PubMed1978

Features of foreign proteins affecting their retrograde transport in axons of the visual system.

The retrograde axoplasmic transport of foreign proteins in the rat visual system shows certain specificities. The molecular features of these proteins which may underlie their entry into the retrograde phase have been examined using biochemical and morphologic techniques. Of the isoenzymes of horseradish peroxidase (HRP), the basic isoenzyme C is strongly transported, while the acidic isoenzymes Abeta and Aalpha are transported weakly and not at all, respectively. Decreasing the isoelectric point (pI) of isoenzyme C from 8.2 to 4.4 decreases its transport, but a basic pI is not the sole requisite for transportability since two other basic peroxidases (turnip isoenzyme P7 and lactoperoxidase) are not transported in retrograde. The sugar component as a whole of isoenzyme C does not appear to be required for determining transport. Isoenzyme C and the other proteins which are transported enter multivesicular bodies in axons and axon terminals, as well as synaptic and coated vesicles and fine tubules in axon terminals. The non-transported proteins enter only the vesicular organelles thought to be involved in neurotransmitter recycling in axon terminals and do not enter multivesicular bodies. Thus the two systems of axonal membraneous compartments involved in local synaptic recycling versus the retrograde phase of transport do not show the same specificity of uptake of extracellular tracers and can be dissociated by the experimental use of these peroxidases.

Animals↗
PubMed1975

Lidocaine effects on brain mitochondrial metabolism in vitro.

Both lidocaine and anoxia inhibit rapid axonal transport. In an attempt to elucidate the mechanism of this action of lidocaine, its effect on mitochondrial respiration was studies. The local anesthetic produces a dose-dependent inhibition of oxygen consumption (50 per cent inhibition at 8mM) by porcine brain mitochondria when glutamate, but not when succinate, serves as the substrate. This indicates electron transport is blocked at the NADH dehydrogenase level. Potent uncoupling of oxidative phosphorylation is observed with both substrates. All of the effects are readily reversible upon removal of the anesthetic. It is concluded that lidocaine apparently inhibits rapid axonal transport by depressing oxidative metabolism.

Animals↗
PubMed1971

Purification and properties of a hydrogenase from Desulfovibrio vulgaris.

The soluble hydrogenase of Desulfovibrio vulgaris was purified and some of its properties are described. The molecular weight was determined for the enzyme by sedimentation equilibrium (45,400) and amino acid analysis (44,800). The hydrogenase appears to be a loosely coiled molecule or to have a high axial ratio, which is reflected in an unusually low sedimentation coefficient (2.58S) and a low diffusion coefficient (D 5.85). The molecular weight of the hydrogenase (41,000), as calculated by the Svedberg equation, was in general agreement with the sedimentation equilibrium molecular weight. Amino acid analysis revealed the presence of six halfcystine residues per mole of enzyme and a total of 417 amino acid residues. The specificity of the hydrogenase and its capacity to reduce certain low potential dyes and cytochrome c(3) was studied. Metal analysis of the hydrogenase indicated the presence of 1 mole of ferrous iron per mole of enzyme.

Absorption↗
PubMed1971

Thiosulfate reductase of Desulfovibrio vulgaris.

The thiosulfate reductase of Desulfovibrio vulgaris has been purified and some of its properties have been determined. Only one protein component was detected when the purified enzyme was subjected to polyacrylamide gel electrophoresis at pH values of 8.9, 8.0, and 7.6. In the presence of H(2), the enzyme, when coupled to hydrogenase and with methyl viologen as an electron carrier, catalyzed the reduction of thiosulfate to hydogen sulfide. The use of specifically labeled (35)S-thiosulfate revealed that the outer sulfur atom was reduced to sulfide and the inner sulfur atom was released as sulfite. Thus, the enzyme catalyzes the reductive dismutation of thiosulfate to sulfide and sulfite. The molecular weight of the enzyme was determined by sedimentation equilibrium (16,300) and amino acid analysis (15,500). The enzyme sedimented as a single, symmetrical component with a calculated sedimentation coefficient of 2.21S. Amino acid analysis revealed the presence of two half-cystine residues per mole of enzyme and a total of 128 amino acid residues. Carbohydrate and organic phosphorus analyses revealed the presence of 9.2 moles of carbohydrate and 4.8 moles of phosphate per mole of enzyme. The substrate specificity of the enzyme was studied.

Acrylates↗