title: Biological recognition of phosphate and sulfate.
abstract: The biological recognition of trigonal pyramids has been studied in a statistical analysis of the Cambridge Structural Data Base. The preferential stereochemistry of pyramidal anion-Lewis acid interactions is easily described for the phosphonyl dianion (R-PO3(2-), as found in the phosphate group) and the sulfonyl monoanion (R-SO3-, as found in the sulfate group) by trans/gauche conformational terminology. Interactions between these pyramidal anions and metals generally prefer gauche geometry (as defined by the R-X = O-Mn+ torsion angle, X = P or S). Interactions between phosphonyls and hydrogen bond donors likewise display a preference for gauche orientation. Interactions between sulfonyls and hydrogen bond donors exhibit a preference for gauche stereochemistry and also cluster in eclipsed regions. These hydrogen bond motifs provide a greater understanding of the function of pyramidal anions in biological structure and function. For example, interactions of the sulfate monoanion are important for the binding of heparin, a sulfated glycosaminoglycan, to antithrombin III.
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia 19104-6323.
authors.forename: Z F
authors.initials: ZF
authors.lastname: Kanyo
authors.forename: D W
authors.initials: DW
authors.lastname: Christianson
mesh_terms: D003461:Crystallography; D006493:Heparin / Q000737:chemistry; D006860:Hydrogen Bonding; D008670:Metals / Q000737:chemistry; D015394:Molecular Structure; D010710:Phosphates / Q000737:chemistry* / Q000502:physiology; D013237:Stereoisomerism; D013431:Sulfates / Q000737:chemistry*
chemical_list: D008670:Metals; D010710:Phosphates; D013431:Sulfates; D006493:Heparin