2-DIMENSIONAL PROTEIN CRYSTALS (S-LAYERS) - FUNDAMENTALS AND APPLICATIONS

Two-dimensional crystalline surface layers (S-layers) composed of prot ein or glycoprotein subunits are one of the most commonly observed pro karyotic cell envelope structures. Isolated S-layer subunits are endow ed with the ability to assemble into monomolecular arrays in suspensio n, on surfaces or interfaces by an entropy-driven process. S-layer lat tices are isoporous structures with functional groups located on the s urface in an identical position and orientation. These characteristic features have already led to applications of S-layers as (1) ultrafilt ration membranes with well-defined molecular weight cut-offs and excel lent antifouling characteristics, (2) immobilization matrices for func tional molecules as required for affinity and enzyme membranes, affini ty microcarriers and biosensors, (3) conjugate vaccines, (4) carriers for Langmuir-Blodgett films and reconstituted biological membranes, an d (5) patterning elements in molecular nanotechnology. (C) 1994 Wiley- Liss, Inc.