Hydrolytic activity of histidine-containing octapeptides in water identified by quantitative screening of a combinatorial library

Abstract

A quantitative on-bead screening of a combinatorial octapeptide library revealed catalysts with hydrolytic activity in water. Histidine is an essential amino acid but the catalytic activity as well as the substrate binding affinity is also dependent on the sequence of the octapeptide.

Alternative application of an affinity purification tag: hexahistidines in ester hydrolysis

“…This observation might also explain the increase that is observed when going from CCMV dimers to capsids: the His-tags are much more surrounded by protein material and the hydrophobic aggregated ELPs in the capsid state than in the dimer state. Another explanation could be the influence of other types of neighboring residues, as it was shown previously that the activity of histidine-containing oligopeptides is sequence dependent 20 .…”

The role of β-hairpin conformation in ester hydrolysis peptide catalysts based on a TrpZip scaffold

“…Thus, studies that used different solvents and ester substrates may not result in sequences that can be directly compared. However, it is notable that prior reports in different reaction conditions are consistent in identifying sequences with multiple His residues as the most active catalysts 7,16,20 even in work where it was hypothesized that a 'catalytic triad' similar to the classical His Ser Asp might emerge from screening. Imidazole functional groups, present in His side chains, are known to catalyze ester hydrolysis, 23,24 so we were curious about the role played by the peptide conformation.…”

“…The study of ester hydrolysis catalysts has been used as a starting point for more challenging hydrolysis reactions, 11 and has important practical applications itself, 12 such as in the depolymerization of polyester plastics. 13,14 Peptide ester hydrolysis catalysts have been reported using a variety of structural scaffolds including b-hairpins, 7,15,16 polyproline helices, 9,17 ahelices, 5 cyclic peptides, 18 dendrimers, 19 and more. 20 Further investigation of the effect of secondary structure is important for determining the role of conformation on catalysis and in guiding the design of future catalysts.…”

“…In the case of b-hairpin ester hydrolysis catalysts, catalytic sequences have been reported that were designed de novo, 15 and that were identied from combinatorial screening. 7,16 Combinatorial screens have been performed using invariant turn-nucleating residues to create a b-hairpin scaffold, and variable positions in the residues oriented on the same face of the b-hairpin (either in the hydrogen bonding or non-hydrogen bonding positions). Sequences that are active ester hydrolysis catalysts can result in rate transformation through a number of effects, including binding to the substrate, altering side chain pK a , and directly playing a role in the catalysis of the transformation as a nucleophile or base.…”

Chemical Biology: What is Its Role in Drug Discovery?

“…Peptides can also be used as catalysts in organic reactions. A library of histidine-containing octapeptides were screened, as potential catalysts, in the hydrolysis reaction of a pyrene ester (Schmuck et al, 2009). Solid supports have been designed to bind selectively to the phosphate group of peptides which allows any non-phosphorylated peptides to be easily removed by filtration (F. Cass & Tepe, 2009).…”