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T T Tchen

Publications and source records attributed to T T Tchen.

At least 73 records · Page 4Linked to original sources
PubMed1972

Turnover of putrescine in a Pseudomonas species.

A Pseudomonas species was found to readily take up labeled putrescine added in trace amounts to any of four growth media, bis-(3-aminopropyl)-amine, 4-aminobutyrate, glucose-NH(3), and Casamino Acids, although the rate of uptake varied considerably from one medium to another. Putrescine degradation, as well as excretion and conversion to hydroxyputrescine, was demonstrated in all four media, indicating that this organism has a constitutive putrescine degradation pathway. The extents of putrescine degradation, excretion, and conversion to hydroxyputrescine are shown for these four growth media through an incubation period of 1 hr. These results document more fully the experimental details behind a previous communication which postulated that the constitutive degradation of putrescine participates in the regulation of intracellular putrescine concentration. The significance of this apparent violation of the general concept that synthetic end products are normally not degraded is discussed.

Amino Acids↗
PubMed1969

Nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate-linked succinic semialdehyde dehydrogenases in a Pseudonomas species.

A Pseudomonas species grown on polyamines was found to have the following enzymes that can dehydrogenate succinic semialdehyde: a constitutive nicotinamide adenine dinucleotide phosphate (NADP)-linked dehydrogenase, an inducible NAD-linked dehydrogenase specific for succinic semialdehyde (EC 1.2.lb), and more than one inducible NAD-linked aminoaldehyde dehydrogenase which can act on succinic semialdehyde, 3-aminopropanal, and 4-aminobutanal. These enzymes have been separated from each other by ammonium sulfate precipitation, column chromatography on diethylaminoethyl-Sephadex, and electrophoresis on polyacrylamide gel. The level of NAD-linked succinic semialdehyde dehydrogenase in cells grown on various C and N sources has been determined and found to be as expected of an inducible enzyme with, however, two slight variations: the basal level of the enzyme in cells grown on Casamino Acids is relatively high and readily detectable, and the level of this enzyme is the same when the cells are grown on gamma-aminobutyrate with or without glucose and is, therefore, not subject to the classical glucose effect.

Aldehydes↗