Effects of methoxychlor, dieldrin and lindane on sea urchin fertilization and early development.

We have studied the effects of methoxychlor (MXC), dieldrin, and lindane on fertilization and early development of sea urchin egg. These organochlorine pesticides have often been found in polluted ground and water near agricultural sites, and have therefore been detected from time to time in the food chain and in drinking water. They have been reported to alter various reproduction functions in various animals including marine populations.

Effect of three xenobiotic compounds on Glutathione S-Transferase in the clam Ruditapes decussatus.

The effects of 4,4'DDE, methoxychlor and imidazole were studied on glutathione S-transferase activities in the gills and hepatopancreas of the clam Ruditapes decussatus. The contamination doses were 0.14 microM for 4,4'DDE, 0.

Structure-based analysis of GPCR function: conformational adaptation of both agonist and receptor upon leukotriene B4 binding to recombinant BLT1.

We produced the human leukotriene B(4) (LTB(4)) receptor BLT1, a G-protein-coupled receptor, in Escherichia coli with yields that are sufficient for the first structural characterization of this receptor in solution. Overexpression was achieved through codon optimization and the search for optimal refolding conditions of BLT1 recovered from inclusion bodies. The detergent-solubilized receptor displays a 3D-fold compatible with a seven transmembrane (TM) domain with ca 50% alpha-helix and an essential disulfide bridge (circular dichroism evidence); it binds LTB(4) with K(a)=7.

Nonpeptide RGD antagonists: a novel class of mimetics, the 5,8-disubstituted 1-azabicyclo[5.2.0]nonan-2-one lactam.

The 1-azabicyclo[5.2.0]nonan-2-one lactam 1 adequately substituted on both cycles A and B as scaffolds mimics the conformationally constrained beta-turn of the tripeptide RGD signaling motif of fibronectin.

Mussel transplantation and biomarkers as useful tools for assessing water quality in the NW Mediterranean.

Mussels, coming from an aquaculture farm located in a clean open bay, were transplanted to several stations of the bays of Nice and Cannes (NW Mediterranean) including a reference site for one month at three periods. Several biomarkers: activities of glutathione S-transferase (GST; exposure to organics), of catalase (exposure to oxidative stress) and of acetylcholinesterase (inhibited by some pesticides) and the lipid peroxidation (thiobarbituric acid reactive substances: TBARS) were measured in transplanted mussels. Cd, Cu and Zn concentrations were also measured as well as their condition index.

Purification and partial characterization of seven glutathione S-transferase isoforms from the clam Ruditapes decussatus.

This paper deals with the purification and the partial characterization of glutathione S-transferase (GST) isoforms from the clam Ruditapes decussatus. For the first step of purification, two affinity columns, reduced glutathione (GSH)-agarose and S-hexyl GSH-agarose, were mounted in series. Four affinity fractions were thus recovered.

Ca release from intracellular stores by thapsigargin in sea urchin eggs: Relationship to larval development and relevance in egg activation.

Thapsigargin (Tg), an inhibitor of microsomal Ca ATPase, is used as a tool to study the changes in Ca sequestration in sea urchin eggs and their relationship to embryonic development. Micromolar amounts of Tg inhibit ATP-dependent Ca sequestration in a dose-dependent and non-reversible manner, depending on the bulk of biological material used. IC values are 1 nmol/L and 1-10μmol/L, respectively, in the cortical Ca stores (isolated cortices preparation) and in digitonin-permeabilized eggs, a preparation giving access to the deeper reticulum compartment.