title: The N-terminal 26-residue fragment of human programmed cell death 5 protein can form a stable alpha-helix having unique electrostatic potential character.
abstract: PDCD5-(1-26) is a N-terminal 26-residue fragment of human PDCD5 (programmed cell death 5) protein. PDCD5 is an important novel protein that regulates both apoptotic and non-apoptotic programmed cell death. The conformation of PDCD5 protein is a stable helical core consisting of a triple-helix bundle and two dissociated terminal regions. The N-terminal region is ordered and contains abundant secondary structure. Overexpression and purification of the N-terminal 26-residure fragment, PDCD5-(1-26), was performed in this study to better understand its tertiary structure. The spectroscopic studies using CD and hetero- and homo-nuclear NMR methods determine a stable alpha-helix formed by Asp3-Ala19 of PDCD5-(1-26). The N-terminal residues Asp3-Ala19 of PDCD5 were then affirmed to have the capacity to form a stable alpha-helix independently of the core of the protein. Analysis of the helical peptide of PDCD5-(1-26) indicates that the surface of this well-formed alpha-helix has a unique electrostatic potential character. This may provide an environment for the N-terminal alpha-helix of PDCD5 to serve as an independent functional entity of the protein. The apoptosis activity assay shows that the deletion of the N-terminal alpha-helix of PDCD5 significantly attenuates the apoptosis-promoting effects on HL-60 cells induced by serum withdrawal.
authors.affiliation: National Laboratory of Biomacromolecules, Center for Molecular Biology, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Liu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Yao
authors.forename: Yaoyao
authors.initials: Y
authors.lastname: Chen
authors.forename: Yingang
authors.initials: Y
authors.lastname: Feng
authors.forename: Yingyu
authors.initials: Y
authors.lastname: Chen
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000737:chemistry* / Q000378:metabolism*; D018922:HL-60 Cells; D006801:Humans; D008958:Models, Molecular; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity
chemical_list: D051017:Apoptosis Regulatory Proteins; D009363:Neoplasm Proteins; C117283:PDCD5 protein, human