title: Surface plasmon resonance imaging biosensor for cathepsin G based on a potent inhibitor: development and applications.
abstract: A specific surface plasmon resonance imaging (SPRI) array biosensor for the determination of the enzymatically active cathepsin G (CatG) has been developed. For this purpose, a specific interaction between an inhibitor immobilized onto a chip surface and CatG in an analyzed solution was used. The MARS-115 CatG peptidyl inhibitor containing the 1-aminoalkylphosphonate diaryl ester moiety at the C terminus and N-succinamide with a free carboxylic function was synthesized and covalently immobilized onto the gold chip surface via the thiol group (cysteamine). Atomic force microscopy was used for the observation of surface changes during the subsequent steps of chip manufacture. Optimal detection conditions were chosen. High specificity of synthesized inhibitor to CatG was proved. The precision, as well as the accuracy, was found to be well suited to enzyme determination. The sensor application for the determination of CatG in white blood cells and saliva was shown for potential diagnosis of leukemia and oral cavity diseases during the early stages of those pathological states.
authors.affiliation: Department of Electrochemistry, Institute of Chemistry, University of Bialystok, 15-443 Bialystok, Poland. ewka@uwb.edu.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Gorodkiewicz
authors.forename: Marcin
authors.initials: M
authors.lastname: Sieńczyk
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Regulska
authors.forename: Renata
authors.initials: R
authors.lastname: Grzywa
authors.forename: Ewa
authors.initials: E
authors.lastname: Pietrusewicz
authors.forename: Adam
authors.initials: A
authors.lastname: Lesner
authors.forename: Zenon
authors.initials: Z
authors.lastname: Lukaszewski
mesh_terms: D015374:Biosensing Techniques; D020134:Catalytic Domain; D056649:Cathepsin G / Q000032:analysis* / Q000097:blood; D006046:Gold / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009059:Mouth Diseases / Q000175:diagnosis; D011480:Protease Inhibitors / Q000737:chemistry*; D040081:Protein Array Analysis; D012463:Saliva / Q000201:enzymology; D013438:Sulfhydryl Compounds / Q000737:chemistry; D020349:Surface Plasmon Resonance
chemical_list: D011480:Protease Inhibitors; D013438:Sulfhydryl Compounds; D006046:Gold; D056649:Cathepsin G