title: P7, a novel antagonist of corticotropin releasing factor receptor type 1 (CRFR1) screened from phage display library.
abstract: The corticotropin releasing factor (CRF) plays a central role in regulating the activities of hypothalamic-pituitary-adrenal (HPA) axis in the presence of a variety of stressful stimuli via binding to its type 1 receptors (CRFR1). Despite that many peptidic or non-peptidic antagonists of CRFR1 have been developed to serve as therapeutic tools to CRF-related pathologies, none of them have been utilized clinically. Targeting the extracellular domain 1 (EC1) of CRFR1, the CRF-binding site, represents a new strategy to inhibit the function of the receptor. However, no such agents have been identified up to now. Herein, by using an 87-amino acid fragment corresponding to the EC1 region as the bait, we screened the binding polypeptides from a phage display (Ph.D.-12) peptide library. After 3-round biopanning, positive clones were selected and the polypeptides carried by them were identified. 5 polypeptides were found to bind with the target specifically. Among them, the P7 exhibited the highest affinity. By evaluating the cAMP accumulation in the CRFR1 or CRFR2-expressing HEK293 cells, we demonstrated that P7 blocking the function of CRFR1, but not CRFR2. In addition, we also found that P7 and CRF act on CRFR1 competitively. Taken together, we reveal that P7, a novel polypeptide identified from phage display library, inhibits the function of CRFR1 effectively and specifically by binding at its EC1 domain. The new polypeptide might provide a promising agent for diagnostic or therapeutic utilities in CRF-related disorders.
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China.
authors.forename: Jinmei
authors.initials: J
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China.
authors.forename: Rengong
authors.initials: R
authors.lastname: Zhuo
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China.
authors.forename: Shuzhuo
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China.
authors.forename: Jianquan
authors.initials: J
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China. Electronic address: weixl@bmi.ac.cn.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Department of Biochemical Pharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, PR China. Electronic address: maxyer22@yahoo.com.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Ma
mesh_terms: D000595:Amino Acid Sequence; D000242:Cyclic AMP / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D018019:Receptors, Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism*; D000099052:CRF Receptor, Type 1
chemical_list: C101531:CRF receptor type 2; D019151:Peptide Library; D010455:Peptides; D018019:Receptors, Corticotropin-Releasing Hormone; D000099052:CRF Receptor, Type 1; D000242:Cyclic AMP
keywords: CRF; CRFR1; CRFR2; Peptide antagonist; Phage display