title: Tick histamine-binding proteins: isolation, cloning, and three-dimensional structure.
abstract: High-affinity histamine-binding proteins (HBPs) were discovered in the saliva of Rhipicephalus appendiculatus ticks. Their ability to outcompete histamine receptors indicates that they suppress inflammation during blood feeding. The crystal structure of a histamine-bound HBP, determined at 1.25 A resolution, reveals a lipocalin fold novel in containing two binding sites for the same ligand. The sites are orthogonally arranged and highly rigid and form an internal surface of unusual polar character that complements the physicochemical properties of histamine. As soluble receptors of histamine, HBPs offer a new strategy for controlling histamine-based diseases.
authors.affiliation: Natural Environment Research Council, Institute of Virology and Environmental Microbiology, Oxford, United Kingdom. gcp@mail.nerc-oxford.ac.uk
authors.forename: G C
authors.initials: GC
authors.lastname: Paesen
authors.forename: P L
authors.initials: PL
authors.lastname: Adams
authors.forename: K
authors.initials: K
authors.lastname: Harlos
authors.forename: P A
authors.initials: PA
authors.lastname: Nuttall
authors.forename: D I
authors.initials: DI
authors.lastname: Stuart
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000502:physiology; D002352:Carrier Proteins / Q000737:chemistry; D003001:Cloning, Molecular; D003461:Crystallography; D015853:Cysteine Proteinase Inhibitors / Q000737:chemistry; D005260:Female; D015870:Gene Expression / Q000502:physiology; D006420:Hemeproteins / Q000737:chemistry; D006632:Histamine / Q000378:metabolism*; D006633:Histamine Antagonists / Q000737:chemistry; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054835:Lipocalin 1; D008297:Male; D008969:Molecular Sequence Data; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D011968:Receptors, Histamine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011969:Receptors, Histamine H1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011970:Receptors, Histamine H2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018100:Receptors, Histamine H3 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013987:Ticks
chemical_list: D002352:Carrier Proteins; D015853:Cysteine Proteinase Inhibitors; D006420:Hemeproteins; D006633:Histamine Antagonists; D019476:Insect Proteins; D054835:Lipocalin 1; D010975:Platelet Aggregation Inhibitors; D011506:Proteins; D012333:RNA, Messenger; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D018100:Receptors, Histamine H3; D012471:Salivary Proteins and Peptides; C080268:moubatin; C090560:nitrophorin; D006632:Histamine