Research in the Pentelute lab will entail the use of chemistry to understand the biological properties of virulence factors and mirror image proteins. The use of chemical methods to investigate proteins is advantageous because the molecule can be tailored at will. These chemically modified proteins will be characterized with modern biophysical techniques such as single-molecule electrophysiology, EPR, protein X-ray crystallography, protein NMR, and biological mass spectrometry. The synthetic protein moieties will be further studied in biological contexts that range from in vitro to in vivo environments.
Protein translocation probed with chemical synthesis
Anthrax toxin will be used to investigate protein translocation across membranes. We aim to prepare semisynthetic anthrax toxin protein constructs and investigate their translocation properties. These studies, that are only made possible by the use of chemistry, will provide unique mechanistic insights into protein translocation across membranes. After these novel approaches have been demonstrated to work in the anthrax toxin system, more complicated toxins such as diphtheria toxin, cholera toxin, botulinum neurotoxin, and shiga-like toxin will be investigated. A new knowledge base will be provided from these studies on how to engineer protein toxins for the delivery D-proteins and other novel chemical entities into cells.
Biological properties of mirror image proteins
The lab will study the biological properties of D- proteins, which are yet to be fully elucidated. D-proteins are the mirror images of the natural occurring L-proteins and can only be made by total chemical synthesis. D-proteins are thought to be non-immunogenic and resistant to proteolysis thereby making them attractive for biological and therapeutic investigation. A major problem in biomedicine is the need for protein scaffolds that mimic antibodies (bind targets with high-affinity and specificity), but are small, stable, long-lived, and non-immunogenic. The lab will chemically synthesize different D-proteins and determine their immunogenicity and pharmacokinetics. Once the superior biological properties of D-proteins have been demonstrated, a combinatorial library of D-monobodies (D-protein antibody mimics) will be created that can be used to select for binders to L-protein targets. By establishing chemical access to a number of D-proteins, their chemical properties can be tailored to maximize the desired biological response. These studies will provide a sound basis for the development of D-proteins as a modern class of intracellular protein therapeutics.