title: Enzymatic activity on a chip: the critical role of protein orientation.
abstract: We compare the catalytic activities of enzymes immobilized on silicon surfaces with and without orientation. While oriented sulfotransferases selectively immobilized on an otherwise zero-background surface via 6xHis tags faithfully reflect activities of solution phase enzymes, those with random orientation on the surface do not. This finding demonstrates that controlling the orientation of immobilized protein molecules and designing an ideal local chemical environment on the solid surface are both essential if protein microarrays are to be used as quantitative tools in biomedical research.
authors.affiliation: Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Taewoon
authors.initials: T
authors.lastname: Cha
authors.forename: Athena
authors.initials: A
authors.lastname: Guo
authors.forename: Xiao-Yang
authors.initials: XY
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D015239:Arylsulfotransferase / Q000378:metabolism*; D002384:Catalysis; D002846:Chromatography, Affinity; D004800:Enzymes, Immobilized / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D018613:Microscopy, Confocal; D008956:Models, Chemical; D040081:Protein Array Analysis; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D012825:Silicon / Q000737:chemistry; D013379:Substrate Specificity; D013499:Surface Properties
chemical_list: D004800:Enzymes, Immobilized; D011506:Proteins; D012821:Silanes; D015239:Arylsulfotransferase; D012825:Silicon