Effect of polyamines on globin synthesis in a rabbit reticulocyte polyamine-free protein synthetic system.
A polyamine-free protein synthetic system, established from components of rabbit reticulocytes, consisted of globin mRNA, salt-washed ribosomes, partially purified initiation factors, and pH 5 enzymes. Spermidine added to this system not only lowered the optimal magnesium concentration required for globin synthesis, but it also stimulated the globin synthesis 6- to 8-fold. The optimal spermidine concentration was 0.4 to 0.6 mM, a concentration similar to that in intact rabbit reticulocytes. The ratio of alpha to beta globin chains synthesized in the presence of spermidine and Mg2+ was approximately 1.0, while the ratio in the presence of only Mg2+ was approximately 1.5. Formation of methionyl puromycin was stimulated 4- to 6-fold by spermidine. This indicates that the stimulation is mainly at the level of initiation.
Ogasawara
T
T
Faculty of Pharmaceutical Sciences, Chiba University.
Ito
K
K
Igarashi
K
K
D000818:Animals; D002474:Cell-Free System; D005914:Globins / Q000096:biosynthesis* / Q000302:isolation & purification; D006160:Guanosine Triphosphate / Q000378:metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000378:metabolism; D011073:Polyamines / Q000494:pharmacology*; D014176:Protein Biosynthesis; D011691:Puromycin / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012343:RNA, Transfer / Q000378:metabolism; D011817:Rabbits; D012156:Reticulocytes / Q000187:drug effects / Q000378:metabolism*; D013095:Spermidine / Q000494:pharmacology
D010448:Peptide Initiation Factors; D011073:Polyamines; D012333:RNA, Messenger; D011691:Puromycin; D006160:Guanosine Triphosphate; D005914:Globins; D012343:RNA, Transfer; D013095:Spermidine