Premium
Conformational properties of the N‐terminal residues of S‐peptide. I. The ribonuclease S′ system
Author(s) -
Filippi Bruno,
Borin Gianfranco,
Anselmi Ugo,
Marchiori Fernando
Publication year - 1978
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1978.360171102
Subject(s) - chemistry , alanine , ribonuclease , serine , peptide , threonine , lysine , proline , stereochemistry , sequence (biology) , s tag , ribonuclease t1 , amino acid , biochemistry , enzyme , rnase p , rna , gene
The contribution of the 1–6 N‐terminal sequence to the conformational properties of the S‐peptide (the 1–20 sequence of ribonuclease A) was assessed by determining in the ribonuclease S′ system the helical content and the binding capability of synthetic [Orn 10 ]‐S‐peptide analogs, in which lysine 1 , glutamic 2 and threonine 3 were progressively deleted, alanine 4 and alanine 5 were alternatively replaced by serine, and alanine 6 was substituted by serine or proline. Both the deletion of the three N‐terminal residues and the alanine 6 /proline replacement produces the loss of the helical structure up to lysine 7 . No or minor effects are found in all other cases. From the comparison of the binding data, the energy for the conformational stabilization of the N‐terminal region was calculated to amount to 1.4 kcal/mol. The results are discussed in comparison with the known x‐ray data of the enzyme, with some predictive rules of secondary structure which were applied to this region and with the known phylogenetic variance of the residues in this region.