Modulation of enzyme-substrate selectivity using tetraethylene glycol functionalized gold nanoparticles.
Tetraethylene glycol (TEG) functionalized gold nanoparticles with 2 nm core diameters (AuTEG) enhance alpha-chymotrypsin (ChT) enzyme activity in a substrate-selective fashion. We explored the hydrolysis of four different substrates and observed a marked increase in activity with the most hydrophobic substrate N-succinyl-alanine-alanine-proline-phenylalanine- p-nitroanilide (TP), while the other substrates remain virtually unaffected by the AuTEG 'crowding effect' in solution. The enhancement in catalysis is indicated by an increase in K(cat)/K(m) as obtained from Lineweaver-Burk analysis and we hypothesize it to arise from a macromolecular crowding effect analogous to that observed with high molecular weight poly(ethylene glycol) (PEG) polymers.
Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA.
Brian J
BJ
Jordan
Rui
R
Hong
Gang
G
Han
Subinoy
S
Rana
Vincent M
VM
Rotello
D000818:Animals; D002384:Catalysis; D002417:Cattle; D002918:Chymotrypsin / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D006868:Hydrolysis; D053758:Nanoparticles / Q000737:chemistry*; D010179:Pancreas / Q000201:enzymology; D011092:Polyethylene Glycols / Q000737:chemistry*; D013379:Substrate Specificity
D011092:Polyethylene Glycols; D006046:Gold; D002918:Chymotrypsin; C117608:alpha-chymotrypsin