Lampreys belong to the class of Cyclostomata; practically no evolution of these Vertebrates can be noted since Paleozoïc times; lampreys thus appear as a choice material for studying several problems in the field of biochemical evolution. Several monomeric haemoglobins can be characterized in the erythrocytes of the sea lamprey (Petromyzon marinus). The major constituent was isolated by chromatography, and submitted to tryptic digestion; soluble tryptic peptides were separated by gel filtration into 5 fractions; the peptides of each fraction were isolated either by Dowex-50 chromatography or by HPLC; the insoluble core was oxidized and submitted to HPLC fractionation. The primary structure of the whole chain and of the purified tryptic peptides was determined using automatic sequencing; alignment of the peptides was achieved by homology with the previously established covalent structure of the globin of Lampetra fluviatilis. The sequence we established confirms the crystallographic data of Hendrickson and Love. Globin/haem contacts are discussed; a tentative explanation of the absence of tetramerization can be proposed after comparison with the aminoacid residues involved in alpha 1 beta 1 and alpha 1 beta 2 contacts. Petromyzon globin differs at three locations (Thr/Ser3, Leu/Met58, Thr/Ser60) from Lampetra fluviatilis globin. The monomeric chain of another Cyclostomata Myxine glutinosa, differs more considerably (88 residues). Our results corroborate recent paleontologic data which favour the separation of lampreys from hagfishes; Cyclostomata cannot be considered as a monophylic group. Finally, there is a closer relation between lamprey globin and alpha chains than between this monomeric globin and beta chains, and furthermore apomyoglobins of higher vertebrates.

Amino Acid Sequence↗

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Calcium and bicarbonate ions mediate the inhibition of mast cell histamine release by Avène spa water.

Avène spa water (ASW) inhibits the histamine release induced in mast cells by substance P; the inhibition is reversed by EDTA and by EGTA. Calcium and magnesium ions, the major cations present in ASW, were experimented in simple saline solutions in the presence of various counter-ions. Only calcium salts inhibited the peptidergic stimulation, with different potencies ruled by the nature of the counter-anion (HCO3- > Cl- > SO4(2)). On a Ca2+ concentration basis, ASW was, however, more inhibitory, suggesting that other compounds present in ASW potentiate the effect of calcium.

Animals↗

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[Reaction of several metabolites of adrenaline with a new nitroso-mercurial reagent].

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Chromatography, Paper↗

PubMedDate not supplied

[Research on ortho-diacetylbenzene, a reagent for amino groups. I. Study of the reaction with amino acids].

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Acetates↗

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[Utilization of various omega-guanidoalkylphosphonic acids by Pseudomonas aeruginosa].

Bacterial growth was studied in synthetic media containing guanidomethyl-, 2-guanidoethyl-, 3-guanidopropyl- or 4-guanido-1-aminobutyl-phosphonic acid, as a possible nitrogen or phosphorus source. Among these four compounds, 2-guanidoethylphosphonic acid (2-GEPh) appeared to be the only efficient nitrogen nutrient. Our results are discussed in light of recent data on Pseudomonas aeruginosa amidinohydrolases. In addition, 2-GEPh proved to be a valuable source of phosphorus; the phosphorus group of its higher homologue 3-guanidopropylphosphonic acid was also used, but the linear bacterial growth curve reflected a limited rate of phosphate release. The characterization of ethylguanidine and propylguanidine in the corresponding culture filtrates suggests a hydrolytic process similar to that described for 3-aminopropylphosphonic acid.

Guanidines↗

PubMedDate not supplied

[Influence of supplementary tyrosine or phenylalanine on bacterial growth and pigmentation of "Pseudomonas aeruginosa" (author's transl)].

Pseudomonas aeruginosa grows readily on synthetic media containing succinate (36 mM) and ammonium chloride as sole source of nitrogen (34 mM) ; addition of tyrosine or phenylalanine (2,7 mM) is followed by an increase of both the growth rate and pyocyanine production. Several molecules structurally related to tyrosine give similar results. Tyrosine partially suppresses the inhibitory effect of both cyanide and azide. The results are discussed with regard to the biosynthesis of aromatic aminoacids and of phenazine pigments.

Azides↗