Pyroglutamyl N-termini of thermal polyamino acids.

It has been established indirectly that the N-termini of the thermal polyamino acids are pyroglutamic acid. This was determined by trifluoroacetic acid hydrolysis of the lactam ring followed by Dansyl labelling. The polyamino acids contained Ala, Gly, Glu, Leu, Phe, and Pro.

Papillomas on fish exposed to chlorinated wastewater effluent.

The presence of carcinogenic and mutagenic chemical(s) in the effluent of a wastewater treatment plant was indicated by papillomas developing on caged black bullheads (Ictalurus melas), hepatic enzyme induction in exposed fish, and Ames test mutagenicity of organic extracts of the wastewater. Although virus-like particles have been reported in papillomas of several other fish species, no evidence was obtained for the presence of viruses in the black bullhead papillomas. Mutagenic and carcinogenic chemicals were not identified in the wastewater, but chlorination was implicated as a factor contributing to the induction of the papillomas.

Peptide separation and isolation with an automated amino acid analyzer.

A technique is presented for separation and collection of amino acids and peptides using a microcolumn amino acid analyzer. By use of the program and the column selection valve of the amino acid analyzer, and without any modification of the instrumentation, the stream of the eluate is diverted into the reaction coil and absorbance is recorded at regular intervals. The rest of the eluate is collected in a fraction collector for further characterization of the separated peptides.

Comparative benzo[a]pyrene metabolite patterns in fish and rodents.

Benzo[a]pyrene is converted to 3-hydroxybenzo[a]pyrene, 9-hydroxybenzo[a]pyrene, benzo[a]pyrene-4,5-dihydrodiol, benzo[a]pyrene-7,8-dihydrodiol, benzo[a]pyrene-9,10-dihydrodiol, and benzo[a]pyrene quinones by postmitochondrial supernatant or microsomes in such fish as the rainbow trout, flounder, salmon, mullet, little skate, Fundulus grandis, and sea catfish. It is also now well-established that many fish convert benzo[a]pyrene to potent mutagenic metabolites as has been demonstrated with the Ames test, especially when the fish are induced with Aroclor 1254 or 3-methylcholanthrene. The metabolite patterns obtained at different substrate concentrations levels indicate that the metabolism is more complex at low concentrations when metabolites are recycled in the in vitro system.