Tetrazolium oxidase polymorphism in rainbow trout

Tetrazolium oxidase from the blood and liver of rainbow trout was found to be genetically polymorphic. The inheritance pattern of the liver enzyme was compatible only with a one locus-two allele hypothesis. The enzymes in the blood while having an electrophoretically identical polymorphism could differ genotypically from that of the liver in a given fish. The significance of these findings to the understanding of the evolution of the salmonid genome is discussed.

Phosphoglycerate kinase: an X-linked polymorphism in man

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Initiation of rabbit hemoglobin synthesis: methionine and formylmethionine at the N-terminal

Ribosome-bound peptides were prepared from rabbit reticulocytes incubated in a reaction mixture that contained all essential amino acids except tryptophan. The peptides were fractionated by Sephadex gel filtration and the N-termini of these peptides were examined. Longer uncompleted hemoglobin chains (larger than 30 amino acids) had unblocked valine at the N-terminal position. In contrast, shorter initial parts of chains (smaller than 16 amino acids) did not have valine at the N-terminal position. These small peptides had methionine at the N-terminal, and 8% of the terminal methionine was presumably formylated. These findings indicate that hemoglobin chains are initiated from methionine or N-formylmethionine (or from both methionine and N-formylmethionine), and that the methionyl residue is hydrolyzed at an early stage of chain elongation.