These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Photopatterning enzymes on polymer monoliths in microfluidic devices for steady-state kinetic analysis and spatially separated multi-enzyme reactions.
    Author: Logan TC, Clark DS, Stachowiak TB, Svec F, Fréchet JM.
    Journal: Anal Chem; 2007 Sep 01; 79(17):6592-8. PubMed ID: 17658765.
    Abstract:
    A method for photopatterning multiple enzymes on porous polymer monoliths within microfluidic devices has been developed and used to perform spatially separated multienzymatic reactions. To reduce nonspecific adsorption of enzymes on the monolith, its pore surface was modified by grafting poly(ethylene glycol), followed by surface photoactivation and enzyme immobilization in the presence of a nonionic surfactant. Characterization of bound horseradish peroxidase (HRP) was carried out using a reaction in which the steady-state profiles of the fluorescent reaction product could be measured in situ and then analyzed using a plug-flow bioreactor model to determine the observed maximum reaction rate and Michaelis constant. The Michaelis constant of 1.9 micro mol/L agrees with previously published values. Mass-transfer limitations were evident at relatively low flow rates but were absent at higher flow rates. Sequential multienzymatic reactions were demonstrated using the patternwise assembly of two- and three-enzyme systems. Glucose oxidase (GOX) and HRP were patterned in separate regions of a single channel, and product formation was analyzed as a function of flow direction. Significant product formation occurred only in the GOX to HRP direction. A three-enzyme sequential reaction was performed using invertase, GOX, and HRP. All possible arrangements of the three enzymes were tested, but significant product formation was only observed when the enzymes were in the correct sequential order. Photopatterning enzymes on polymer monoliths provides a simple technique for preparing spatially localized multiple-enzyme microreactors capable of directional synthesis.
    [Abstract] [Full Text] [Related] [New Search]