Search results for "Palinuridae"
showing 6 items of 6 documents
Updated distribution and first description of Scyllarus subarctus (Crustacea: Scyllaridae) decapodid stage
2019
Este artículo contiene 8 páginas, 4 figuras, 2 tablas.
Fluorescence labels as sensors for oxygen binding of arthropod hemocyanins
2004
The molecular basis of high cooperativity in multi-subunit proteins is still unknown in most cases. Oxygen binding by multi-subunit hemocyanins produces two intrinsic spectroscopic signals which are, however, either limited to the UV or are very weak. Here we demonstrate that fluorescence labels emitting in the visible can be used as sensors for cooperative oxygen binding of hemocyanins. Fluorescence resonance energy transfer to the oxygenated active sites quenches the emission of the labels by roughly 50% upon oxygenation of the protein. The labels give strong and photo-stable emission, allowing imaging of single hemocyanin molecules. Therefore, this study opens up a new perspective for in…
Molecular characterisation and evolution of the hemocyanin from the European spiny lobster, Palinurus elephas.
2003
The hemocyanin of the European spiny lobster Palinurus elephas (synonym: Palinurus vulgaris) is a hexamer composed by four closely related but distinct subunits. We have obtained the full cDNA sequences of all four subunits, which cover 2275-2298 bp and encode for native polypeptides of 656 and 657 amino acids. The P. elephas hemocyanin subunits belong to the alpha-type of crustacean hemocyanins, whereas beta- and gamma-subunits are absent in this species. An unusual high ratio of non-synonymous versus synonymous nucleotide substitutions was observed, suggesting positive selection among subunits. Assuming a constant evolution rate, the P. elephas hemocyanin subunits emerged from a single he…
Behavioural and biochemical stress responses of Palinurus elephas after exposure to boat noise pollution in tank
2014
This study examined the effects of boat noise on the behavioural and biochemical parameters of the Mediterranean spiny lobster (Palinurus elephas).The experiment was conducted in a tank equipped with a video and audio recording system. 18 experimental trials, assigned to boat noise and control conditions, were performed using lobsters in single and group of 4 specimens. After a 1. h habituation period, we audio- and video-recorded the lobsters for 1. h. During the experimental phase, the animals assigned to the boat groups were exposed to boat noise pollution (a random sequence of boat noises). Exposure to the noise produced significant variations in locomotor behaviours and haemolymphatic …
Quaternary structure of the European spiny lobster (Palinurus elephas) 1x6-mer hemocyanin from cryoEM and amino acid sequence data.
2002
Abstract Arthropod hemocyanins are large respiratory proteins that are composed of up to 48 subunits (8×6-mer) in the 75 kDa range. A 3D reconstruction of the 1×6-mer hemocyanin from the European spiny lobster Palinurus elephas has been performed from 9970 single particles using cryoelectron microscopy. An 8 A resolution of the hemocyanin 3D reconstruction has been obtained from about 600 final class averages. Visualisation of structural elements such as α-helices has been achieved. An amino acid sequence alignment shows the high sequence identity (>80%) of the hemocyanin subunits from the European spiny lobster P. elephas and the American spiny lobster Panulirus interruptus . Comparison of…
Kinetic properties of hexameric tyrosinase from the crustacean Palinurus elephas.
2008
Tyrosinases catalyze hydroxylation of monophenols to o-diphenols and their subsequent oxidation to o-quinones, whereas catecholoxidases catalyze only the latter reaction. Both enzymes occur in all organisms and are Type 3 copper proteins that perform the first steps of melanin formation. In arthropods, they play an essential role in the sclerotization of the exoskeleton. Very few phenoloxidases are characterized structurally or kinetically and the existence of an actual tyrosinase activity has not been demonstrated in most cases. Here we present for the first time a complete kinetic characterization of a tyrosinase from a crustacean (Palinurus elephas) including the influence of inhibitors.…