title: Nitric oxide-induced conformational changes in soluble guanylate cyclase.
abstract: Soluble guanylate cyclase (sGC) is the primary mediator of nitric oxide (NO) signaling. NO binds the sGC heme cofactor stimulating synthesis of the second messenger cyclic-GMP (cGMP). As the central hub of NO/cGMP signaling pathways, sGC is important in diverse physiological processes such as vasodilation and neurotransmission. Nevertheless, the mechanisms underlying NO-induced cyclase activation in sGC remain unclear. Here, hydrogen/deuterium exchange mass spectrometry (HDX-MS) was employed to probe the NO-induced conformational changes of sGC. HDX-MS revealed NO-induced effects in several discrete regions. NO binding to the heme-NO/O2-binding (H-NOX) domain perturbs a signaling surface implicated in Per/Arnt/Sim (PAS) domain interactions. Furthermore, NO elicits striking conformational changes in the junction between the PAS and helical domains that propagate as perturbations throughout the adjoining helices. Ultimately, NO binding stimulates the catalytic domain by contracting the active site pocket. Together, these conformational changes delineate an allosteric pathway linking NO binding to activation of the catalytic domain.
authors.affiliation: Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Underbakke
authors.affiliation: Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Iavarone
authors.affiliation: Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Chalmers
authors.affiliation: Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Pascal
authors.affiliation: Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Novick
authors.affiliation: Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Griffin
authors.affiliation: Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA. Electronic address: marletta@scripps.edu.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Marletta
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain; D006152:Cyclic GMP / Q000737:chemistry*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006162:Guanylate Cyclase / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000737:chemistry*; D011485:Protein Binding; D017510:Protein Folding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D000071756:Soluble Guanylyl Cyclase
chemical_list: D021122:Protein Subunits; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D006152:Cyclic GMP