Open AccessPeptidyl‐Donor Substrates for Ribosomal Peptidyl Transferase
Author(s) -
Mercer Julian F. B.,
Symons Robert H.
Publication year - 1972
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1972.tb01881.x
Subject(s) - peptidyl transferase , chemistry , ribosome , stereochemistry , phenylalanine , ribosomal rna , ribosomal protein , transferase , acetic anhydride , biochemistry , amino acid , catalysis , enzyme , rna , gene
A study of the structural requirements for activity of low molecular weight compounds in the donor or peptidyl site of ribosomal peptidyl transferase requires methods for the chemical synthesis of potential donor substrates. Methods are described here for the preparation of cytidylyl‐(3′→ 5′)‐cytidylyl‐(3′→ 5′)‐2′(3′)‐ O ‐( N ‐[ 3 H]acetyl‐ l ‐leucyl)‐adenosine and cytidylyl‐(3′→ 5′)‐2′(3′)‐ O ‐( N ‐[ 3 H]acetyl‐ l ‐leucyl)‐adenosine and the corresponding l ‐phenylalanine derivatives. A major difficulty overcome was the severe restriction placed on possible synthetic routes by the extreme alkali lability of the aminoacyl linkage. The synthetic route developed involved the stepwise synthesis of CpCpA and CpA appropriately protected with acid‐labile protecting groups. The free terminal 2′(3′)‐hydroxyls were aminoacylated, all protecting groups removed and the α‐amino groups acylated with [ 3 H]acetic anhydride. The chemically prepared N ‐acetyl‐aminoacyl‐trinucleotide fragments had similar activity in the ribosome‐catalysed fragment reaction as reported for the corresponding pentanucleotide fragments obtained from biological sources. Further, the inactivity of the N ‐acetyl‐aminoacyl‐dinucleotide fragments was confirmed under a wider range of conditions than those previously described.