Creative BioMart is a well-known expert who is committed to incorporating a variety of non-canonical amino acids into proteins to introduce new functions, redesign natural proteins and artificial protein macromolecules. With years of experience, we provide customized services for unnatural backbone amides proteins to precisely meet customer requirements.

Introduction of Backbone Amides

The backbone amides in the main secondary structure elements in proteins are hydrogen bonded. In order to estimate the contribution of main chain hydrogen bonding to protein folding, backbone modifications have been made by incorporation of unnatural amino acids that lack H-bonding capability. Strategies to achieve this are primarily substitution of primary amides with secondary amides via proline substitution, amide substitution with dimethylene or thiomethyl groups, or substitution with esters or trans-alkenes, allowing examination of folding stability and functional skeleton hydrogen bonding. Significant progress has been made in modeling protein secondary and quaternary structures through non-naturally folded backbones.

Fig 1. Examples of unnatural backbone substitutions made in place of amides (A) and α-amino acid residues (B) in the context of folded protein tertiary structures. (Reinert Z E, et al., 2014)

Services

Scientists now extend the scope of protein engineering from side chain substitution to include modifications to the polypeptide backbone itself. As a leading service provider of protein engineering, Creative BioMart has successfully incorporated unnatural backbone elements at one or more points in the natural sequence of proteins. We attempted to enhance the influence of backbone hydrogen bonds on protein structure and thermodynamic stability of unfolded proteins through protein backbone changes.

All proteins contain a characteristic backbone formed by consecutive amide bonds, and backbone amide-mediated hydrogen bonds play a key role in most aspects of protein structure and function. Traditional technologies that only allow sidechain replacement are limited. Our scientists allow manipulation of protein backbones using techniques such as nonsense suppression mutagenesis and protein ligation. We offer the following strategies to examine backbone-mediated hydrogen bonding by replacing backbone amide groups with ester groups, including:

• PDZ domains: PDZ domains are scaffolding modules in protein-protein interactions. We addressed this interaction by generating semisynthetic PDZ domains containing backbone amide-to-ester mutations and evaluating the importance of individual hydrogen bonds for ligand binding.
• Aromatic backbone amides: we introduce an aromatic ring, and the interaction between the side chain aromatic ring and the hydrogen of the main chain amide (Ar HN) and the CH of the aliphatic group (π-CH) can stabilize the secondary structure of peptides and proteins.

Creative BioMart is committed to enhancing the role of backbone-mediated hydrogen bonding in protein recognition, folding, function and structure by providing non-natural backbone (amide-to-ester mutagenesis) proteins to global customers. We will work with you to develop the most appropriate strategy and provide the most meaningful data for your research for accelerating the research of life sciences. If you are interested in our services, please do not hesitate to contact us for more information.

Reference

1. Reinert Z E, Horne W S. (2014) Protein backbone engineering as a strategy to advance foldamers toward the frontier of protein-like tertiary structure[J]. Organic & biomolecular chemistry. 12 (44): 8796-8802.

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