Putrescine and spermidine were the dominant polyamines in Tetrahymena cells. Spermine was present only in very small amounts. Changes in the amount of putrescine during and after the synchronizing heat treatment followed a definite quantitative pattern. Changes in the amount of spermidine were similar, though not so pronounced. The changes may be due to a varied influx of polyamines into the ce...

Putrescine, 1,4-diaminobutane, is an intermediate in the biosynthesis of more complexed polyamines, spermidine and spermine. Unlike other eukaryotes, plants have evolved a multistep pathway for putrescine biosynthesis that utilizes arginine. In the final reaction, N-carbamoylputrescine is hydrolyzed to putrescine by N-carbamoylputrescine amidohydrolase (CPA, EC 3.5.1.53). During the hydrolysis,...

Prolonging the marketing period of peach fruits in Egypt through introducing new cultivars, breaking dormancy early or delaying maturity of some cultivars by safe compounds would increase the growers' profits. This study was conducted during two successive seasons 2005 and 2006 by using "Desert Red" peach cultivar (Prunus persica L.) grafted on Nemaguard rootstock. Trees were grown at El-Noubar...

The polyamines putrescine, spermidine, and spermine are organic cations that are required for cell growth and differentiation. Ornithine decarboxylase (ODC), the first and rate-limiting enzyme in the polyamine biosynthetic pathway, catalyzes the conversion of ornithine to putrescine. As the polyamine biosynthetic pathway is essential for the growth and survival of Leishmania donovani, the causa...

The administration of [14C]putrescine or [14C]spermidine (i.v., 100 muCi) to normal volunteers or patients with advanced cancer resulted in alpha-phase half-lives of 40 and 30 sec and beta-phase half-lives of 30 and 60 min, respectively. No significant differences were found between the plasma decay curves of normals and those of cancer patients. Urinary excretion was similar with both groups e...

Development eggs of the polychete Ophryotrocha labronica were analyzed for polyamines during the first 6 days after fertilization. The spermine content dominated initially, but gradually decreased. It was surpassed by putrescine, which rapidly increased to a maximum on the 3rd day, i.e., at the inception of grastrulation. The spermidine content was low during the entire period. Treatment of egg...

PotF protein is a periplasmic substrate-binding protein of the putrescine transport system in Escherichia coli. We have determined the crystal structure of PotF protein in complex with the substrate at 2.3-A resolution. The PotF molecule has dimensions of 54 x 42 x 30 A and consists of two similar globular domains. The PotF structure is reminiscent of other periplasmic receptors with a highest ...

Histidine, lysine, ornithine, and tyrosine decarboxylase activities were tested in 38 strains of Staphylococcus (15 of S. equorum, 11 of S. epidermidis, 7 of S. saprophyticus, and 5 of S. pasteuri) and 19 strains of Bacillus (13 of B. subtilis and 6 of B. amyloliquefaciens) isolated from two Spanish traditional sausage varieties. The four decarboxylase activities were present in most of the str...

The cellular accumulations of polyamines and ribonucleic acid (RNA) were compared in the polyauxotrophic mutants of Escherichia coli strain 15 TAU and E. coli K-12 RC(re1) met(-) leu(-). Putrescine, spermidine, and their monoacetyl derivatives were the main polyamines in both strains, when grown in glucose-mineral medium. No significant degradation of either (14)C-putrescine or (14)C-spermidine...

Introduction The polyamine, putrescine, was first isolated from putrefying meat but is thought to play an important role in cell growth and differentiation ([1]). It also generates succinate via GABA and can thus serve as an energy source to the small intestine ([2]). Elevated plasma putrescine levels have been reported in an endotoxic rodent model ([3]). We have previously characterized a 72 h...