title: Plasmonic ruler on field-effect devices for kinase drug discovery applications.
abstract: Protein kinases are cellular switches that mediate phosphorylation of proteins. Abnormal phosphorylation of proteins is associated with lethal diseases such as cancer. In the pharmaceutical industry, protein kinases have become an important class of drug targets. This study reports a versatile approach for the detection of protein phosphorylation. The change in charge of the myelin basic protein upon phosphorylation by the protein kinase C-alpha (PKC-α) in the presence of adenosine 5'-[γ-thio] triphosphate (ATP-S) was detected on gold metal-insulator-semiconductor (Au-MIS) capacitor structures. Gold nanoparticles (AuNPs) can then be attached to the thio-phosphorylated proteins, forming a Au-film/AuNP plasmonic couple. This was detected by a localized surface plasmon resonance (LSPR) technique alongside MIS capacitance. All reactions were validated using surface plasmon resonance technique and the interaction of AuNPs with the thio-phosphorylated proteins quantified by quartz crystal microbalance. The plasmonic coupling was also visualized by simulations using finite element analysis. The use of this approach in drug discovery applications was demonstrated by evaluating the response in the presence of a known inhibitor of PKC-α kinase. LSPR and MIS on a single platform act as a cross check mechanism for validating kinase activity and make the system robust to test novel inhibitors.
authors.affiliation: Department of Electronic & Electrical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom. Electronic address: N.Bhalla@bath.ac.uk.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Bhalla
authors.affiliation: Department of Electronic & Electrical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom. Electronic address: N.Fornisano@bath.ac.uk.
authors.forename: Nello
authors.initials: N
authors.lastname: Formisano
authors.affiliation: Department of Electronic & Electrical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom. Electronic address: A.Miodek@bath.ac.uk.
authors.forename: Anna
authors.initials: A
authors.lastname: Miodek
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, USA. Electronic address: ajain17@iastate.edu.
authors.forename: Aditya
authors.initials: A
authors.lastname: Jain
authors.affiliation: Department of Chemical Engineering, University of Bath, Bath BA2 7AY, United Kingdom. Electronic address: M.Di.Lorenzo@bath.ac.uk.
authors.forename: Mirella
authors.initials: M
authors.lastname: Di Lorenzo
authors.affiliation: Department of Pharmacy & Pharmacology, University of Bath, Bath BA2 7AY, United Kingdom. Electronic address: G.Pula@bath.ac.uk.
authors.forename: Giordano
authors.initials: G
authors.lastname: Pula
authors.affiliation: Department of Electronic & Electrical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom. Electronic address: P.Estrela@bath.ac.uk.
authors.forename: Pedro
authors.initials: P
authors.lastname: Estrela
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002460:Cell Line; D055808:Drug Discovery / Q000295:instrumentation*; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D004676:Myelin Basic Protein / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051571:Protein Kinase C-alpha / Q000378:metabolism*; D058525:Quartz Crystal Microbalance Techniques; D012666:Semiconductors; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D004676:Myelin Basic Protein; C022571:adenosine 5'-O-(3-thiotriphosphate); D006046:Gold; D000255:Adenosine Triphosphate; D051571:Protein Kinase C-alpha
keywords: Drug discovery; Localized surface plasmon resonance; Metal-insulator-semiconductor; Nanoplasmonics; Protein phosphorylation