Effect of iron and hexachlorobenzene on liver haem biosynthesis

The original publication is available at http://www.samj.org.za[No abstract available]Publisher’s versio

Gamma-aminobutyric acid CSF

[No abstract available]Lette

Phosphorylation increases α-bungarotoxin binding to acetylcholine receptor-enriched membrane preparations

Acetylcholine receptor (AChR)-enriched membrane preparations from Torpedo electroplax bind α-bungarotoxin with a K(D) of 8.4 nM and the concentration of binding sites is 16 pmoles/mg protein. When, however, the α-toxin is incubated with receptor samples, phosphorylated in the presence of Mn2+ (10 mM) and ATP (0.5 mM), the concentration of binding sites is increased to 94 pmoles/mg protein, although there is no marked change in the K(D) (11 nM). Binding of acetylcholine to AChR-enriched membrane preparations occurs at a receptor which has two different conformational states with K(D)'s of 8.4 nM and 520 nM. The concentration of binding sites for the high affinity components is 1.35 pmoles/mg protein and for the low affinity component is 12 pmoles/mg protein. The effect of phosphorylation of the AChR on agonist binding could not be determined.Articl

Characterization and quantitation of alpha-adrenergic receptor subtypes in rat hypothalamus

The binding of [3H]dihydroergocryptine ([3H]-DHE) to rat hypothalamic membranes was examined. Displacement of [3H]-DHE by 100 nM phentolamine, prazosin and clonidine can be used to assay for total α-, α1- and α2-adrenergic receptor sites respectively. The α1-adrenergic receptor content of the hypothalamus is 4.1 pmoles/g tissue whereas the α2-level is 6.5 pmoles/g tissue. [3H]-WB 4101 (α1 selective) and [3H]clonidine (α2 selective) binding yielded similar levels of 3.2 and 5.8 pmoles/g tissue. It is concluded that [3H]-DHE is a suitable ligand for the assay of α-adrenergic receptor subtypes under the conditions determined in this study.Articl

Characterization of protein phosphorylation in acetylcholine receptor-enriched membrane preparations from torpedo fuscomaculata

When the acetylcholine receptor (AChR*) from Torpedo is phosphorylated, ATP is found to bind non-covalently to the preparation. After correction is made for this binding of ATP, the phosphorylation reaction has a Km of 0,16 mM, a pH optimum of 8,6 and reaches maximal activity within 3 min. The intrinsic kinase activity is very specific for the AChR and does not phosphorylate either histones or phosvitin. The only amino acid to be phosphorylated is serine and cyclic GMP causes stimulation of the reaction. © 1982 Martinus Nijhoff/Dr W. Junk Publishers.Articl

There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two

Ras, V., Neethling, S., Engelbrecht, A., Morandini, A.C., Bayha, K.M., Skrypzeck, H., Gibbons, M.J. (2020): There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two. Zootaxa 4778 (3): 401-438, DOI: https://doi.org/10.11646/zootaxa.4778.3.

V. RAS, S. NEETHLING, A. ENGELBRECHT, A.C. MORANDINI, K.M. BAYHA, H. SKRYPZECK & M.J. GIBBONS (2020) There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two Zootaxa, 4778: 401-438.

Ras, V., Neethling, S., Engelbrecht, A., Morandini, A.C., Bayha, K.M., Skrypzeck, H., Gibbons, M.J. (2020): V. RAS, S. NEETHLING, A. ENGELBRECHT, A.C. MORANDINI, K.M. BAYHA, H. SKRYPZECK & M.J. GIBBONS (2020) There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two Zootaxa, 4778: 401-438. Zootaxa 4852 (5): 600-600, DOI: 10.11646/zootaxa.4852.5.1