Matthew R. Callstrom

Feature articls. Doped glassy carbon: a new material for electrocatalysis

Glassy carbon is an important material for electrochemical catalysis, particularly as an electrode material. Current methods for the preparation of glassy carbon are described, together with a discussion of recent progress in the modification of the surface of glassy carbon. Surface modification of glassy carbon, with the intent of mediating its electrochemical behaviour, remains an important research topic. Methods to achieve this goal, including surface absorption of electrochemically active species, covalent attachment of active species and coating the surface of glassy carbon with thin films, are reviewed briefly. We describe a new low-temperature approach to preparing homogeneously modified, rather than surface modified, glassy carbon, using the thermolysis of poly(phenylene diacetylene)s as the carbon solid precursor. This methodology is compatible with the introduction of a wide variety of heteroatoms, including nitrogen, silicon and fluorine, and allows the preparation of thin films of glassy carbon. The incorporation of platinum in various oxidation states is described and the electrochemical response of the platinum-doped glassy carbons is described.

The Use of Carbohydrate Protein Conjugates of Proteases [CPC(Proteases)] for the Catalytic Formation of Peptide Bonds

The discovery of catalysts that can selectively couple unprotected peptide fragments would revolutionize protein chemistry by allowing convergent polypeptide synthesis. Proteolytic enzymes have the capability to perform this chemistry because the protein can specifically recognize and bind to C-terminal and N-terminal peptide sequences, activate the C-terminal peptide sequence by forming an acyl-enzyme intermediate, and couple the two peptide fragments together. However, barriers that limit the use of proteases as catalysts for convergent peptide synthesis include (i) the stability of proteolytic enzymes in organic solvent systems; (ii) a simple and effective C-erminal and N-terminal protecting group strategy; and (iii) the isolation of the polypeptide product from the reaction mixture. In the previous paper we reported the stabilization of enzymes by the covalent attachment of proteins through their ο-lysine residues to a series of carbohydrate-based macromolecules. In this paper we report the use of carbohydrate protein conjugates of proteases [CPC(proteases)] as catalysts for peptide bond synthesis and a general strategy for convergent oligopeptide synthesis.

New carbohydrate-based materials

We have prepared a series of new carbohydrate-based materials based on the use of carbohydrates as a template for the introduction of functionality to polymeric materials with complete regio- and stereochemical control. The synthesis of these new materials by the use of chemical and enzymatic methods allows for the rational design of new materials based on the properties of the monomeric subunit. These materials have potential applications that range from their use in enhanced oil recovery to biodegradable plastics to biological applications including targeted drug delivery and enzyme stabilization.