robe Microscopy and the and Metalloenzymes: Se

Allen Hi& O.xford Uni~e~s~~, hited Kingdom

The ~ev~~op~~ent of bioelectrochemistry over the past quarter of a ~e~~ur~ has c~~~e~trat~~ oh 6he behaviour ,>f ~eta~lop~ote~~s and metalloenzymes at electrode surfaces and, of course, the app~i~at~o~s to bio~~~~~~~~a~ ~~~rnist~~. However, our understanding of such systems rests on the behaviour of such systems at, or on, electrode sarfa~es. The Advent of methods of applying Scanning Probe Microscopy in water opened up the possib~~~~ of studying ~~~~o~~~~~ rn~~e~u~es under conditions appropriate to their natural functions and hence one could assume that they were not s~~~~~~~~~t~y changed in their structures or functions. Though the first protein examined was the zinc-containing protein, ~~~ta~~~~~io~~i~, we have concentrated on azurin and cytochrome P450 and its partner proteins, ~utidaredoxin (Pd)and ~~ti~~a~~d~~~~ ~~d~ct~~e (PdR). In particular, we bave sought conditions that allow the investigation of structures of the corn iexes formed between ~ytochrome P459 and Pd and PdR. With all these expermiments, it was impo~a~t to show that the proteins were SUE active when adsorbed on the electrode surface and, as expected, it was usually important to modify the surface with a promoter (or, more recently, a faciiitator.) We are now attempting to study the eie~troc~emist~ of the proteins under these ~o~~~t~~~s and to move the proteins into organised arrays in preparation for the use of similar systems as tru!y rn~~~~~~ar sensors. The investigation of the ubiquitous glucose sensor by Scanning Tunneling Mi~ros~~~y under ~o~dit~o~s c]oseEy related to those found in devices proved possible.

ects of Molecular Engine tons: Ligand Binding, Cat

ho Morishima, Kyoto UniversiQ, Japan

ave been conceded with rational redesign of the structures ofheme proteins in order t diversity of natural beme proteins and to generate novel heme proteins of potential utihty of proteins have revealed that proteins structures are constructed by ‘modules’, which are an correspond to exons on gene structure. In addition to the conventional point mutation, the the ‘module’ substitution on the protein structure as the effective rational design step, and second step, the p ~rn~o~ant role in a

or random.mutations for the fine-tuning. By inserting or sMhstit~ting the specific module ~~ay~~~ an ired function, we can expect that the starting point might

We “nave studied molecular engineering of heme proteins to better und~rsta~ with particular focus on putidaredoxin (electrondonor)-induced ~onformatio~al c

ase to catalase and to position the oxidizing equivalents in peroxidase to the calcium binding site in myoglobin in which the calcium binding mo

and oxygen bindin ffinity is modulated by calcium binding. ckimeric globins to ange the protein-protein recognition chara r&ted b subunit of bemo~iobi~ or myo bin having the module M4 from the a-subuni

4 plays a crucial role in the specific subunit association in gl association properties with other proteins will be presented. So no homology have resulted in quite unstable proteins. We have directed evolution, which allows us to construct novel and stab