Recognition of envelope and tat protein synthetic peptide analogs by HIV positive sera or plasma

A series of synthetic peptides corresponding to segments of HIV encoded proteins were selected using criteria described by Welling et al. [(1985) FEBS Lett. 188, 215]. Synthetic peptide analogs to gp120 (2-13), (55-65), gp41 (582-596) (659-670) and tatIII (71-83) were recognized by 41-67% of sera or plasma from individuals known to be infected with HIV on the basis of virus isolation or Western blot screening. The peptide which reacted with most sera or plasma was gp41 (582-596), a conserved region in the transmembrane glycoprotein. An extended peptide analog, gp41 (579-599), tested against the same samples showed almost 100% reactivity, confirming independent studies identifying a highly immunodominant region of gp41. There was an unexpected high prevalence of antibodies (25%) to the tatIII peptide.     

Agonistic behaviour,responses to a novel object and some aspects of maintenance behaviour in feral-strain and domestic chickens

Feral-strain fowl, bred from birds captured on North-West Island (24°S, 150°E), were compared with domestic chickens hatched and raised under similar conditions. Aspects of behaviour considered included agonistic behaviour and responses to unfamiliar environments and objects. There were many similarities between the feral and domestic fowl in behaviour, but there were also many differences between the strains.Feral cockerels showed higher levels of agonistic behaviour than domestic cockerels, under some conditions. There were differences between young feral and Leghorn-cross chickens in the “freezing” response to handling and placement in an unfamiliar cage, with the feral chickens responding more rapidly.Feral cockerels showed a greater initial avoidance of a novel object than did Black Australorp bantam cockerels, but after a short interval they spent more time near the novel object than the bantams.These results are discussed in relation to selection pressures under conditions of domestication, and on North-West Island.     

Hydrazinolysis-N-reacetylation of glycopeptides and glycoproteins. Model studies using 2-acetamido-1-N-(L-aspart-4-oyl)-2-deoxy-beta-D-glucopyranosy lamine

2-Acetamido-1-N-(L-aspart-4-oyl)-2-deoxy-beta-D-glucopyranosyla mine (1) was used as a model glycopeptide to study the hydrazinolysis-N-reacetylation procedure. The major, initial product was the beta-acetohydrazide derivative of 2-acetamido-2-deoxy-D-glucose (2) which gave 2-acetamido-2-deoxy-D-glucose (5) after exposure to acidic conditions. Very mild conditions of hydrolysis of 2 gave a 75-80% overall yield of 5 from 1 after the hydrazinolysis-N-reacetylation procedure. Several other minor compounds were detected which were not converted into 5 upon mild acid hydrolysis, indicating that 20-25% of product cannot be recovered as 5 at the reducing end of oligosaccharides.     

Behavioural and ecological aspects of nuptial flights of the termitophilous phorids Termitophilomyia zimbraunsi and Mesopathusa modesta (Diptera: Phoridae) in Zimbabwe

Nuptial flights of Termitophilomyia zimbraunsi were observed over three years (1990-1993) near the open chimney of an Odontotermes transvaalensis mound in Harare, Zimbabwe. Copulating phoretic pairs landed on the chimney; males quickly disengaged and flew away whilst females ran inside the vent and tore off their wing membranes. Agitated termite workers and soldiers swarmed the rim in a partially successful physical attempt to expel the phorids; the termites appeared to anticipate the threat of invasion. After acquiring the scent of the nest, female phorids ran underground to lay their large single eggs, probably in the hosts'fungus gardens. Nuptial flights occurred throughout the year but only in the early mornings, peaking in the hot dry season and being least in the hot wet season. The flights were highly temperature dependent (15.0-17.9 °), usually occurring at relatively low light intensities but across a wide range of humidities. Phoresy and sexual dimorphism in wings, mouthparts, food and division of labour in T. zimbraunsi are discussed, as is its termitophilous habit and the responses of termites to it.
Although the females of Mesopathusa modesta are apterous, nuptial flight behaviour is very similar to that of T. zimbraunsi. Neither phorid is host-specific, both species having been found on both Odontotermes latericius and O. transvaalensis mounds, although M. modesta is more common on O. latericius mounds.     

Characterisation of microtubule-associated proteins at the synapse: absence of MAP 2

The high molecular weight microtubule-associated proteins MAP 1 and MAP 2 are major components of brain cytosol and can be readily identified using polyacrylamide gel electrophoresis on the basis of heat-stability and co-sedimentation with microtubules. An examination of synaptosomal cytosol, synaptic plasma membrane and postsynaptic density fractions showed that MAP 2 is absent from these fractions and thus from both pre- and postsynaptic sites. All of the fractions contained polypeptides that comigrated with MAP 1 and a MAP 1 like polypeptide was identified in a microtubule preparation from synaptosomal cytosol. The absence of MAP 2 from synaptosomal cytosol was confirmed by immunoblotting using an antibody directed against MAP 2. Immunocytochemistry using this antibody showed that MAP 2 was present in cell bodies and dendrites but absent from axons.     

A set of surface proteins common to the circulating human platelet and lymphocyte (Short Communication)

The surface proteins of the circulating human platelet and lymphocyte were labelled by using the lactoperoxidase iodination method. Polyacrylamide-gel electrophoresis showed that four corresponding labelled proteins are found on the surface of each cell type. The most intensely labelled protein contains little or no carbohydrate, but the remaining labelled proteins are all glycoproteins. The major labelled band from each cell was isolated and comparative peptide ;maps' showed that the two proteins are closely similar. The surface proteins of the lymphocyte and platelet are distinct from those on the erythrocyte, the remaining major type of circulating cell.     

Protein kinase activities in rat liver nuclei: Effects of age and partial hepatectomy

Selective substrates and inhibitors have been used to measure kinases phosphorylating endogenous proteins in rat liver nuclei during growth and regeneration after partial hepatectomy. Peaks in activity were found at 5, 22, and 29 hours after partial hepatectomy. Administration of ₁ and adrenergic blockers suggested that the Be²⁺ sensitive and cyclic AMP-dependent protein kinases were interdependently regulated by Ca²⁺ and cyclic AMP.