Noncovalent Synthesis of Protein Dendrimers

Abstract

The covalent synthesis of complex biomolecular systems such as multivalent protein dendrimers often proceeds with low efficiency, thereby making alternative strategies based on noncovalent chemistry of high interest. Here, the synthesis of protein dendrimers using a strong but noncovalent interaction between a peptide and complementary protein is proposed as an efficient strategy to arrive at dendrimers fully functionalized with protein domains. The association of S-peptide to S-protein results in the formation of an active enzyme (ribonuclease S) and therefore serves as an ideal system to explore this synthetic approach. Native chemical ligation was used to couple four S-peptides by means of their C-terminal thioester to a cysteine-functionalized dendritic scaffold, thus yielding a tetravalent S-peptide wedge. A fully functional ribonuclease S tetramer was prepared by addition of four equivalents of S-protein. Biophysical techniques (isothermal titration calorimetry (ITC), surface plasmon resonance (SPR), and mass spectrometry) and an enzymatic activity assay were used to verify the formation of the multivalent complex. The noncovalent synthetic strategy presented here provides access to well-defined, dynamic, semisynthetic protein assemblies in high yield and is therefore of interest to the field of nanomedicine as well as biomaterials.

Survey of the year 2009: applications of isothermal titration calorimetry

“…In 2009 we identified more than 400 articles after searching Web of Science, PubMed, SciDir and OVID databases using ‘isothermal AND titration AND calorimetry’ or ITC or ‘Isothermal Titration Calorimetry’ search terms. These have been classified into the following categories: Pre‐2009 references cited in the text and review articles 1–43 Protein‐protein and protein‐peptide interactions 44–124 Protein/peptide‐small molecule interactions 125–218 Protein/peptide‐metal ion interactions 219–253 Protein/peptide‐nucleic acid interactions 254–273 Protein/peptide‐lipid interactions 274–292 Protein/peptide‐polysaccharide interactions 293–316 Nucleic acid‐small molecule interactions 317–348 Small molecule interactions …”

Highly Enantioselective Construction of Polycyclic Spirooxindoles by Organocatalytic 1,3‐Dipolar Cycloaddition of 2‐Cyclohexenone Catalyzed by Proline‐Sulfonamide

“…Some creative strategies have been developed to construct protein nanostructures based on molecular recognition, such as symmetry, metal ion induction, or supramolecular interactions 1. Some protein nanostructures, such as artificial protein nanowires,1a protein rings,1b and protein spheres,1c have been created by these strategies and applied in catalysis, tissue imaging, diagnostics, and therapeutic treatments. Among them, host–guest supramolecular interactions have provided desirable driving forces in a reversible and bioorthogonal manner.…”

Survey of the 2009 commercial optical biosensor literature

“…Full references for the 316 papers that were given the thumbs up are provided in the reference section. To make this list useful as a tool for identifying examples of the various assay formats, the citations are subgrouped by reviews/protocols dedicated to biosensor studies, kinetic, equilibrium/competition, or concentration analyses, qualitative formats (e.g., yes/no, screening, epitope mapping),…”