Occurrence of norspermine in Euglena gracilis

Effect of various polyamine analogs on in vitro polypeptide synthesis

Various polyamine analogs were examined for their ability to stimulate and to function as sparing agents for the Mg2+ requirement in polypeptide synthesis at various temperatures in Escherichia coli (37 and 47 degrees C) and the extremely thermophilic Thermus thermophilus (60 and 70 degrees C) cell-free systems. The optimal concentration of each polyamine analog increased as the incubation temperature was elevated. At a fixed temperature, the optimal concentration of polyamine analogs was in the order diamines greater than triamines greater than tetraamines greater than pentaamines. All diamines tested stimulated polypeptide synthesis almost equally but lowered the optimal Mg2+ concentration in the order diaminopropane greater than putrescine greater than cadaverine. The degree of diamine stimulation was maximal at 37 degrees C. The effects of three triamines were very similar in the E. coli system but in the T. thermophilus system spermidine was most effective in stimulation of polypeptide synthesis. From the results of experiments using tetraamines and pentaamines, it was deduced that the presence of both aminobutyl and aminopropyl groups in polyamine analogs is important for stimulation of polypeptide synthesis. In the E. coli system, triamines were the most effective polyamines for stimulation of polyphenylalanine synthesis at both 37 and 47 degrees C, while, in the T. thermophilus system, thermospermine, a tetraamine, was most effective at 60 degrees C and 3,4,4,3-pentaamine was most effective at 70 degrees C.

Polyamines in Trichomonas vaginalis

Trichomonas vaginalis was grown in a modified Bushby's medium and putrescine, spermidine and spermine levels were determined in extracts from 24- and 48-h cultures and also in the culture media. All three polyamines were present in T. vaginalis extracts; the putrescine level and putrescine/spermidine ratio were much higher than those reported for other protozoa or for mammalian tissues. There were no significant differences between 24-h and 48-h amine levels per mg protein in these extracts, but amine levels per cell were higher at 24 than at 48 h. The spent culture media had a much higher putrescine content than corresponding uninoculated media and it was concluded that T. vaginalis secreted putrescine into the culture medium.

Studies on polyamine biosynthesis in Euglena gracilis

Euglene gracilis (strain Z) was found to contain five polyamines which could be separated by high-pressure cation-exchange chromatography. 1,3-Diaminopropane, putrescine, norspermidine (N-(3-aminopropyl)-1,3-diaminopropane), spermidine and norspermine (N,N'-bis(aminopropyl)-1,3-diaminopropane) were identified. Biosynthesis of putrescine in E. gracilis proceeds through decarboxylation of L-ornithine, no arginine decarboxylase (EC 4.1.1.19) activity could be detected. The properties of the enzymes ornithine decarboxylase (EC 4.1.1.17) and S-adenosylmethionine decarboxylase (EC 4.1.1.50) in this alga were found to be similar to those of the enzymes isolated from animal tissues or yeast cells. A bioxynthetic scheme is proposed which relates the different polyamines occurring in E. gracilis.