Putrescine biosynthesis in mammalian tissues

Putrescine catabolism in mammalian brain.

In contrast with putrescine (1,4-diaminobutane), which is a substrate of diamine oxidase, monoacetylputrescine is oxidatively deaminated both in vitro and in vivo by monoamine oxidase. The product of this reaction is N-acetyl-gamma-aminobutyrate. The existence of a degradative pathway in mammalian brain for putrescine is shown, which comprises acetylation of putrescine, oxidative deamination of...

Multiple pathways of putrescine biosynthesis in Escherichia coli.

Urea production and putrescine biosynthesis by Escherichia coli.

Cultures of Escherichia coli B and K-12 produce urea during growth in minimal medium. Results of isotopic labeling experiments were consistent with the sole source of urea being from the conversion of arginine to putrescine. Since E. coli itself has no demonstrable urease activity, the rate of urea production is a measure of the flux through the arginine to putrescine pathway.

Ethylene biosynthesis in fruit tissues.

Tracer studies with avocado tissues indicate that methionine is converted to ethylene at stages of the climacteric rise and the climacteric peak, but not at the preclimacteric stage. The results suggest that the control of ethylene biosynthesis is at a step after methionine is synthesized. The endogenous content of methionine was found to be so low that methionine must be actively turned over f...

The biosynthesis of spermidine and spermine from putrescine and methionine.

Putrescine, NHz(CH&NHZ, spermidine, NHz(CH&NH(CH&NHt, and sperminc, NH2(CH&NH(CH&NH(CH&NHt, are naturally occurring polyamines (for bibliography see ref. 6). That they have physiological significance is suggested by the following: they have been shown to be essential growth factors for Hemophilus injluenza (7-9) and for a mutant of Aspergillus nidulam (lo), and to stimulate the growth of Lactob...