A phylogenetic tree was constructed from 245 globin amino acid sequences. Of the six plant globins, five represented the Leguminosae and one the Ulmaceae. Among the invertebrate sequences, 7 represented the phylum Annelida, 13 represented Insecta and Crustacea of the phylum Arthropoda, and 6 represented the phylum Mollusca. Of the vertebrate globins, 4 represented the Agnatha and 209 represented the Gnathostomata. A common alignment was achieved for the 245 sequences using the parsimony principle, and a matrix of minimum mutational distances was constructed. The most parsimonious phylogenetic tree, i.e., the one having the lowest number of nucleotide substitutions that cause amino acid replacements, was obtained employing clustering and branch-swapping algorithms. Based on the available fossil record, the earliest split in the ancestral metazoan lineage was placed at 680 million years before present (Myr BP), the origin of vertebrates was placed at 510 Myr BP, and the separation of the Chondrichthyes and the Osteichthyes was placed at 425 Myr BP. Local "molecular clock" calculations were used to date the branch points on the descending branches of the various lineages within the plant and invertebrate portions of the tree. The tree divided the 245 sequences into five distinct clades that corresponded exactly to the five groups plants, annelids, arthropods, molluscs, and vertebrates. Furthermore, the maximum parsimony tree, in contrast to the unweighted pair group and distance Wagner trees, was consistent with the available fossil record and supported the hypotheses that the primitive hemoglobin of metazoans was monomeric and that the multisubunit extracellular hemoglobins found among the Annelida and the Arthropoda represent independently derived states.

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Autoxidation of bovine oxymyoglobin to metmyoglobin induces co-oxidation of epinephrine to adrenochrome. This co-oxidation is markedly inhibited by superoxide dismutase [EC 1.15.1.1]. Electron transfer from oxymyoglobin to ferricytochrome c is partially inhibited by superoxide dismutase. These results indicate that autoxidation of oxymyoglobin results in generation of superoxide radicals. Autoxidation of oxymyoglobin is accelerated by superoxide dismutase and partially inhibited by catalase [EC 1.11.1.6].

Mortality of patients who underwent percutaneous endoscopic gastrostomy appears to be high. In particular, the long-term prognosis was poor for patients with hypoalbuminemia, and this procedure is probably not preferred for patients with recurrent aspiration pneumonia.

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The constituent polypeptide chains I, II, III and IV of the giant extracellular haemoglobin of the oligochaete Lumbricus terrestris were isolated by mono Q ion-exchange chromatography and C8 reverse-phase chromatography. The N-terminal amino acid sequences of Lumbricus chains I, III and IV were determined and aligned with those of Lumbricus chain II and the four chains of the extracellular haemoglobin of the polychaete Tylorrhynchus heterochaetus. Three invariant amino acid residues, Cys-7, Val-15 and Trp-19, were found to occur in the N-terminal segments (17-22 residues) of the eight chains of Lumbricus and Tylorrhynchus haemoglobins. In addition, it was found that the eight sequences could be separated into two groups: 'A', consisting of Lumbricus chains I and II and Tylorrhynchus chains I and IIA, having invariant Lys-14 and Lys-16, and 'B', consisting of Lumbricus chains III and IV and Tylorrhynchus IIB and IIC, having invariant Cys-6, Ser-8 and Asp-11. This result suggests that there are two strains of globin chain in the annelid extracellular haemoglobins.

Electrospray ionization mass spectrometry (ESI-MS) of the native, reduced, and carbamidomethylated forms of the extracellular, 3.38-MDa hemoglobin from the marine polychaete Tylorrhynchus heterochaetus, when combined with a maximum entropy (MaxEnt) analysis, provided a complete description of the polypeptide chain composition. This hemoglobin, a hetero-multimeric complex of approximately 180 polypeptide chains, consisting of globin and linker subunits in an approximately 3:1 mass ratio, is among the largest protein complexes investigated by ESI-MS. The globin subunits consist of a monomer subunit (chain I, 15575.4 Da) and a disulfide-bonded trimer subunit, 50068.4 Da, consisting of globin chains IIA (16601.9 Da), IIB (16680.4 Da), and IIC (16,794.0 Da). Linker subunits L1-L5, 23233.8, 24835.4, 25326.9, 28202.2, and 26317.2 Da, respectively, were found together with a disulfide-bonded dimer of L2, 52609.4 Da. Using the exact masses of the subunits, a plausible model of the hemoglobin consisting of 144 globin chains (36 monomers and 36 trimers) and 36 linker chains provides a calculated mass of 3.42 MDa.