The interface between biological molecules and synthetic materials represents a major research frontier that has potential applications in medical diagnostics, disease treatment, pathogen detection and monitoring, and industrial catalysis. Key to these applications is the availability of efficient chemical technologies for the attachment of synthetic components to specific locations on complex protein and nucleic acid surfaces. Although a number of time-tested strategies already exist for this purpose, they are generally difficult to control and costly to use on large scale. Additionally, most of these strategies generate complex mixtures of products leading to poorly-defined materials. In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division, Matthew B. Francis of the University of California, Berkeley, will develop a new enzyme-based reaction for the incorporation of proteins and nucleic acids in synthetic materials. Relative to other methods, this technique can modify complex proteins in single locations and relies on inexpensive building blocks that are available on any desired scale. The program yields a powerful technology that can be used to combine any protein with virtually any material of interest through well-defined linkages. Outreach activities supported by this program spark science interest in K-5 students in local schools. Classroom presentations based on "Chemistry and Biology in the Kitchen" are being developed. The presentations will include memorable and engaging demonstrations of chemical concepts using marshmallows, chocolate, blue berries, and other foods kids love.
The chemistry in this program is based on a series of oxidative coupling reactions that generate ortho-quinone and ortho-iminoquinone intermediates. These intermediates can react with anilines, N-terminal prolines, and free cysteine side chains of various materials with very high rates to yield highly stable conjugates. This class of reactions has been found to work with a full range of biological functional groups attached to polymers, chromophores, and nanoparticles. Previously, this reaction was initiated by the addition of oxidants, such as ferricyanide or periodate. We explore an enzyme-catalyzed method that has similar efficiency using atmospheric oxygen as the oxidant and producing water as the sole byproduct. Specific goals of this program include (1) demonstrating the utility of the technique on a series of interesting protein substrates, (2) optimizing the enzyme component of the reaction to afford greater catalytic efficiency and storage stability, and (3) showcasing the application of the new chemistry to the modification of cellulosic substrates, such as paper and cotton to produce low-cost, biodegradable materials for water purification.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
