Proteomics: capacity versus utility

Until recently scientists studied genes or proteins one at a time. With improvements in technology, new tools have become available to study the complex interactions that occur in biological systems. Global studies are required to do this, and these will involve genomic and proteomic approaches. High-throughput methods are necessary in each case because the number of genes and proteins in even the simplest of organisms are immense. In the developmental phase of genomics, the emphasis was on the generation and assembly of large amounts of nucleic acid sequence data. Proteomics is currently in a phase of technological development and establishment, and demonstrating the capacity for high throughput is a major challenge. However, funding bodies (both in the public and private sector) are increasingly focused on the usefulness of this capacity. Here we review the current state of proteome research in terms of capacity and utility.     

Strategy for sequencing oligopeptides using positive and negative ion laser desorption fourier transform mass spectrometry

A laser desorption Fourier transform mass spectrometric (LD/FTMS) method that uses both positive and negative ion LD/FT mass spectra obtained with collision-activated dissociation has been developed for analysis of oligopeptides. The technique is demonstrated using the model compound gramicidin D, for which the correct sequence is derived using only LD/FTMS information. Different relationships between positive and negative ion spectra are found for linear and cyclic oligopeptides.     

Ligand-enforced intimacy between a gold cation and a carbenium ion: impact on stability and reactivity

Controlling the reactivity of transition metal complexes by positioning non-innocent functionalities around the catalytic pocket is a concept that has led to significant advances in catalysis. Here we describe our efforts toward the synthesis of dicationic phosphine gold complexes of general formula [(o-Ph₂P(C₆H₄)Carb)Au(tht)]²⁺ decorated by a carbenium moiety (Carb) positioned in the immediate vicinity of the gold center. While the most acidic examples of such compounds have limited stability, the dicationic complexes with Carb⁺ = 9-N-methylacridinium and Carb⁺ = [C(Ar^N)₂]⁺ (Ar^N = p-(C₆H₄)NMe₂) are active as catalysts for the cycloisomerization of N-propargyl-4-fluorobenzamide, a substrate chosen to benchmark reactivity. The dicationic complex [(o-Ph₂P(C₆H₄)C(Ar^N)₂)Au(tht)]²⁺, which also promotes hydroarylation and enyne cyclization reactions, displays a higher catalytic activity than its acridinium analog, indicating that the electrophilic reactivity of these complexes scales with the Lewis acidity of the carbenium moiety. These results support the role of the carbenium unit as a non-innocent functionality which can readily enhance the activity of the adjacent metal center. Finally, we also describe our efforts toward the generation and isolation of free γ-cationic phosphines of general formula [(o-Ph₂P(C₆H₄)Carb)]⁺. While cyclization into phosphonium species is observed for Carb⁺ = [C(Ar^N)₂]⁺, [C(Ph)(Ar^N)]⁺, and 9-xanthylium, [(o-Ph₂P(C₆H₄)-9-N-methylacridinium)]⁺ can be isolated as an air stable, biphilic derivative with uncompromised Lewis acidic and basic properties.

This work describes the synthesis of carbenium-based, γ-cationic phosphines and their coordination to Au(i) cations , leading to carbophilic catalysts whose activity is enhanced by the ligand-enforced convergence of the positively charged moieties.     

Cyclotron production of rhodium-101m from natural palladium radiochemical methods and preliminary biological studies

Rh coordination complexes having anticancer properties have been known since 1931.^101mRh has excellent decay properties and can be used to study the biological behaviour of Rh-complexesin vivo. A method for its production using cyclotron technology is described. The yields for¹⁰¹Pd,¹⁰⁰Pd,^101mRh, and¹⁰⁰Rh, produced by proton bombardment of natural Pd, are reported for proton energies from 40- to 60-MeV.^101mRh thick-target yields of 0.9 m Ci/μAh at 32.7 h EOB were measured. A method is proposed to prepare No Carrier Added (NCA)^101mRh in a chemical form suitable for labeling and/or clinical research,^101mRh-chloride,^101mRh-acetate, and^101mRh-DTPA complexes were prepared and used to determine theirin vivo distribution in tumor-bearing laboratory animals. Results of these studies indicated the kidneys and liver being the primary rarget organs. However, bone and tumor uptakes for^101mRh-DTPA were significantly different, with bone levels continuing to increase at 48-h and tumor levels maximizing at ≈24-h post administration. The half-life of^101mRh was measured as 4.26±0.01 days. Work presented at the Second International Symposium on Radiopharmaceutical Chemistry, July 3–7, 1978, Oxford, England.     

A comparison of different types of gold–carbon composite electrode for detection of arsenic(III)

A study has been conducted using abrasively modified basal and edge-plane graphite, carbon-paste, and carbon–epoxy electrodes to create gold–carbon composite electrodes. Using either nano or micro-sized gold particles their suitability for use in detecting arsenic(III) is assessed. It was found that gold arrays prepared from micron-sized particles gave the best performance for arsenic detection. In particular micron arrays produced in carbon-paste electrodes with an easily renewable surface work well for detection of arsenic, producing a detection limit of 5(±2)×10^–9 mol L^–1, with a high sensitivity of 10(±0.1) A mol^–1 L.     

Nachweis und Bestimmung anorganiseher Bestandteile bei Mensch und Tier

Ohne Zusammenfassung     

Effects of anti-GLUT antibodies on glucose transport into human erythrocyte ghosts

We have studied the effects of anti-GLUT1 antibodies on the uptake of glucose into erythrocytes. Glucose transport into human erythrocyte ghosts was measured directly using 3H-2-deoxy-glucose, or indirectly by monitoring associated volume changes using light scattering. The uptake of glucose was significantly inhibited in ghosts resealed in solutions containing specific antibodies against GLUT1. Such an effect was not observed when an antibody against the oestrogen receptor, lacking specificity towards GLUT1, was employed instead. The antibodies were also without effect on the efflux of preloaded glucose from erythrocyte ghosts. The demonstration that anti-GLUT antibodies can inhibit glucose uptake is support for the hypothesis that they exaggerate the cytoplasmic barrier to glucose uptake created by endofacial segments of GLUT1.