Porous silicon: an effective nucleation-inducing material for protein crystallization

Protein crystals play a pivotal part in structural genomics, hence there is an urgent requirement for new and improved methodology to aid crystal grow th. Considerable effort has been invested in the search of substances (nucl eants) that will induce efficient nucleation of protein crystals in a contr olled manner. To date, nucleation has been facilitated mainly by seeding, e pitaxy, charged surfaces or mechanical means. A different approach is intro duced here, involving the use of a mesoporous material that is likely to co nstrain protein molecules and thereby encourage them to aggregate in crysta lline order. Large single crystals were obtained using porous silicon at co nditions that are not sufficient for spontaneous nucleation, for five out o f six proteins that were investigated. We propose that this success is due to the size distribution of pores in the specialty designed porous silicon. (C) 2001 Academic Press.