Proteolytic activity at quantum dot-conjugates: kinetic analysis reveals enhanced enzyme activity and localized interfacial "hopping".
Recent studies show that polyvalent, ligand-modified nanoparticles provide significantly enhanced binding characteristics compared to isolated ligands. Here, we assess the ability of substrate-modified nanoparticles to provide enhanced enzymatic activity. Energy transfer assays allowed quantitative, real-time measurement of proteolytic digestion at polyvalent quantum dot-peptide conjugates. Enzymatic progress curves were analyzed using an integrated Michaelis-Menten (MM) formalism, revealing mechanistic details, including deviations from classic MM-behavior. A "hopping" mode of proteolysis at the nanoparticle was identified, confirming enhanced activity.
Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States.
W Russ
WR
Algar
Anthony
A
Malonoski
Jeffrey R
JR
Deschamps
Juan B
JB
Blanco-Canosa
Kimihiro
K
Susumu
Michael H
MH
Stewart
Brandy J
BJ
Johnson
Philip E
PE
Dawson
Igor L
IL
Medintz
D000818:Animals; D019187:Cadmium Compounds / Q000737:chemistry; D002417:Cattle; D031541:Fluorescence Resonance Energy Transfer; D007700:Kinetics; D008958:Models, Molecular; D010179:Pancreas / Q000201:enzymology; D010455:Peptides / Q000737:chemistry*; D059748:Proteolysis; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D014357:Trypsin / Q000737:chemistry / Q000378:metabolism*; D017967:Zinc Compounds / Q000737:chemistry
D019187:Cadmium Compounds; D010455:Peptides; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; D014357:Trypsin; C031238:zinc sulfide