Biomedical subjects

Sergey N Savinov

Publications and source records attributed to Sergey N Savinov.

6 recordsLinked to original sources

PubMed2005

Engineering an affinity tag for genetically encoded cyclic peptides.

Peptide expression libraries are valuable probes of cellular function. SICLOPPS technology merges the principal advantages of both genetic methods and small-molecule approaches in yielding superior library sizes of operationally stable, structurally well-defined entities with an established biological and medicinal record. Here, we describe development, application, and the first-generation library implementation of an expressed affinity tag for a library of cyclic peptides. A tripeptide streptavidin-binding motif (HPQ) proved to be compatible with presentation from a backbone cyclized template. A resulting peptide was employed as a sensitive indicator of peptide splicing, expression, and recovery as well as an affinity tag for one-step purification. Specific recognition of the tag by streptavidin was also critical for an analysis of intein mutants. Finally, the initially identified probe was used as a template for design of a streptavidin-responsive cyclic peptide library.

Amino Acid Motifs↗

PubMed2004

A systematic method for identifying small-molecule modulators of protein-protein interactions.

Discovering small-molecule modulators of protein-protein interactions is a challenging task because of both the generally noncontiguous, large protein surfaces that form these interfaces and the shortage of high-throughput approaches capable of identifying such rare inhibitors. We describe here a robust and flexible methodology that couples disruption of protein-protein complexes to host cell survival. The feasibility of this approach was demonstrated through monitoring a small-molecule-mediated protein-protein association (FKBP12-rapamycin-FRAP) and two cases of dissociation (homodimeric HIV-1 protease and heterodimeric ribonucleotide reductase). For ribonucleotide reductase, we identified cyclic peptide inhibitors from genetically encoded libraries that dissociated the enzyme subunits. A solid-phase synthetic strategy and peptide ELISAs were developed to characterize these inhibitors, resulting in the discovery of cyclic peptides that operate in an unprecedented manner, thus highlighting the strengths of a functional approach. The ability of this method to process large libraries, coupled with the benefits of a genetic selection, allowed us to identify rare, uniquely active small-molecule modulators of protein-protein interactions at a frequency of less than one in 10 million.

Carrier Proteins↗

PubMed2003

Investigation of an antibody-ligase. Evidence for strain-induced catalysis.

Catalytic antibody 16G3, a peptide ligase with extended substrate scope has been characterized mechanistically exploiting a set of systematically designed perspective substrates 6-9, two of which, thioesters 8 and 9 act instead as inhibitors. Taken together the structure/activity relationships suggest a catalytic mechanism dependent on induction of strain, programmed via specific structural deviations between the hapten and the substrates. General mechanistic implications for de novo induced catalysis are presented.

Antibodies↗

PubMed2002

Peptide-small molecule hybrids via orthogonal deprotection-chemoselective conjugation to cysteine-anchored scaffolds. A model study.

The feasibility of an orthogonal deprotection-conjugation protocol, holding the promise of libraries of functionally diverse chemical probes attached to cysteine-anchored peptide scaffolds, has been explored with a model system. The necessary tools for assembly of the hybrid libraries have been prepared and the tandem procedure optimized. S-alkylation and S-sulfenylation are featured as the chemoselective ligation reactions. [reaction: see text]

Ascorbic Acid↗

PubMed2002

Modular evolution of a chiral auxiliary for the 1,3-dipolar cycloaddition of isomünchnones with vinyl ethers.

[reaction: see text]. The 1,3-dipolar cycloaddition reaction has long been recognized as a powerful methodology in organic synthesis. More recently, this reaction has become a popular manifold for the construction of chemical diversity. Herein, we report the development of a chiral template for the facially selective cycloaddition of isomünchnones, a common class of 1,3-dipoles. The modular format of the asymmetric unit allowed a systematic optimization of selectivity. In addition, the chiral auxiliary was removed through an unusually facile ester aminolysis.

Amino Acids↗

PubMed2002

Diastereofacial solid phase synthesis and self-promoted cleavage of a [2.2.1] bicyclic diversity scaffold.

[reaction: see text]. We have previously described a diastereofacially selective 1,3-dipolar cycloaddition reaction of isomünchnones with vinyl ethers. While adapting this methodology for solid phase synthesis, we discovered a chemoselective and self-promoted linker aminolysis that provides liberated product in high purity, at a significantly enhanced rate. Herein we describe the implementation of a chiral auxiliary as a solid-phase linker, the detailed investigation of its unique aminolysis, and the utility of this cleavage within a chemical diversity format.

Amino Acids↗