Polyphenylalanine synthesis

LI 2 treatment Ribosome binding (pmol/pmol ribosome) Polyphenylalanine synthesis (pmol) Acetylation (pmol)... 

The protein was oxidized and reduced as described in Table 3. This table and the assays for binding of L12 to depleted ribosomes, poly(U>directed polyphenylalanine synthesis, and enzymatic acetylation of L12 to form L7 are from Caldwell and coworkers37. 

If poly(U)-dependent polyphenylalanine synthesis is to be measured, the amount of template to be used is 5 fig/reaction mixture, the Mg acetate concentration is increased to 12 mM, and the amino acid mixture is omitted. 

Fig. 4. Kinetics of polyphenylalanine synthesis at different temperatures, and Arrhenius plots of poly(phe) synthesis in S. solfataricus and E. coli poly-U programmed cell-free systems. Rates of polyphenylalanine synthesis were calculated from the initial slopes of the incorporation kinetics at different temperatures [Cammarano, P, unpublished results].

Optimal conditions for polyphenylalanine synthesis and tightness of subunit interaction in archaea ... 

Effect of aminoglycoside antibiotics on the fidelity and efficiency of polyphenylalanine synthesis in... 

Altamura et al. [178] and Londei et al. [179] investigated the ability of SOS and 30S subunits from phylogenetically disparate archaea to form synthetically active hybrid ribosomes with subunits from bacteria and eucarya, in the presence of Mg " concentrations (lS-18mM) which are optimal for polyphenylalanine synthesis. With poly(U) as the template and Phe-tRNA (or [jV-acetyl-Phe]-puromycin) as the substrate, SOS and 30S subunits from Euryarchaeota (M vannielii) and Crenarchaeota (5. solfataricus) could be assembled into hybrid active monosomes in all reciprocal combinations surprisingly, however, both reciprocal combinations of archaeal (S. solfataricus, M. vannielii) and eucaryal S. cerevisiae) ribosomal subunits gave rise... 

EF)T, (30) supports polyphenylalanine synthesis poorly. It is hydrolysed to guanosine-3, 5 -dipyrophosphate (31) by EF G and ribosomes. A chemical synthesis of (31) has been described. ... 

Evidence also indicates that 16-membered-ring macrolides, as peptidyltransferase inhibitors, hinder the polyuridylic acid-dependent polymerization of phenylalanine, despite the fact that 14-membered-ring macrolides are not able to inhibit polyphenylalanine synthesis. In particular, 16-membered-ring macrolides containing at least one disaccharide-monoglycoside in their structures, such as leucomycin, spiramycin, carbomycin, and tylosin, may cause degradation of polyribosome [93,94]. 

The effect of 8 on in vitro protein synthesis in which poly(U) functions as a messenger RNA (where a UUU sequence is a codon for phenylalanine) was also examined. In the presence of 0.558 mM (r = 1) and 5.58 mM of 8 (r = 10), the polyphenylalanine synthesis underwent 15 % and 26 % inhibition, respectively. We propose a new mechanism for the inhibition of protein synthesis as depicted below. 

Yukioka M, Morisawa S. Studies on the mechanic of action of gougeiotin. (I) Enhance mem of polyphenylalanine synthesis by gougerorin. J Bioebem 1969 66c2Z5-232. 

In 1962 Speyer, Basilio and I proved the validity of a hypothesis by Spotts and Stanier according to which the difference between streptomycin-sensitive, resistant and dependent E. coli. resides in the structure of their ribosomes. We established that streptomycin inhibits poly(U) directed polyphenylalanine synthesis in a fractionated cell-free protein synthesizing system only if the ribosomes in the system are taken from streptomycin-sensitive cells. These results indicated that in sensitive cells streptomycin inteiieres with ribosome action. As subsequent studies revealed, streptomycin is only one among many antibiotics whose site of action is the ribosome. 

Lucas-Lenard, J. and Lipmann, F. (1967) Initiation of polyphenylalanine synthesis by A -acetyl-phenylalanyl-sRNA. Proc. Nat. Acad. Sci. U.S.A. 57, 1050-1057. 

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