6 research outputs found
Konformációs viszonyok és elektronszerkezet-változások vizsgálata fehérjékben = Investigation of conformational fluctuations and electronic structure variations in proteins
FeltĂ©rkĂ©peztĂĽk a foszfoglicerát kináz molekuláris felismerĂ©si folyamataiban szerepet játszĂł konformáciĂłs változásokat. ElvĂ©geztĂĽk a foszfoinozitol kináz 3 alfa izoformájánnak 3D szerkezetpredikciĂłját, azonban a ligandumkötĹ‘dĂ©s vizsgálatára a kooperálĂł partner elállása miatt nem kerĂĽlt sor. FelderĂtettĂĽk a tetrahidribiopterin (BH4) kofaktor szerepe a nitrogĂ©n monoxid szintetáz (NOS) aktiválĂłdásában. Meghatároztuk a NO kötĹ‘helyĂ©t a nitroforin 4 (NP4) fehĂ©rje aktĂv helyĂ©n. Low-mode (LMOD) keresĂ©sen alapulĂł platfromfĂĽggetlen konformerkeresĹ‘ Ă©s dokkolĂł eljárást dolgoztunk ki, amely az AMBER programcsomagban is hozzáfĂ©rhetĹ‘. ElvĂ©geztĂĽk a kifejlesztett eljárás több konformerkeresĹ‘ mĂłdszerrel törtĂ©nĹ‘ összehasonlĂtĂł vizsgálatát. Eljárást dolgoztunk ki humán P450 2C9 ligandumok azonosĂtására Ă©s az izoforma specificitás vizsgálatára a 2C családban. FelderĂtettĂĽk a NADH kofaktor Ă©s NO kölcsönhatás szerepĂ©t a P450 NO-reduktáz fehĂ©rjĂ©ben. A támogatott idĹ‘szak alatt megkezdett hisztamin receptorok kutatását Ă©rintĹ‘ vizsgálataink alapján Ăşj lipofil zsebet találtunk a H1 receptorban, ligandum informáciĂłkkal segĂtett homolĂłgiamodellezĂ©ssel előállĂtottuk a H4 receptor elsĹ‘ atomi felbontásĂş modelljĂ©t Ă©s eljárást dolgoztunk ki Ăşj H4 ligandunok azonosĂtására. UtĂłbbi eljárást az eddig ismert legkiterjedtebb szerkezet alapĂş szűrĹ‘vizsgálatban alkalmazva Ăşj, kĂsĂ©rletileg is megerĹ‘sĂtett H4 ligandumokat azonosĂtottunk. | Conformational motions responsible for the substrate recognition in phosphoglycerate kinase have been explored. Homology model for phosphoinositol 3 kinase alpha isoform has been developed, however docking studies were suspended due to the changed interest of the partner (ComGenex Inc). The role of tetrahydrobiopterin cofactor in nitric oxide synthase has been clarified. The putative nitric oxide binding site in nitrophorin 4 has been identified. A platform-independent LMOD conformational search method has been developed and integrated to AMBER package at UCSF. The performance of this method has been evaluated and compared to other algorithms. A new virtual screening protocol has been developed for the identification of CYP 2C9 ligands. The protocol was useful for isofom specificity studies in the 2C family. The role of NADH-nitric oxide interaction in P450-No reductase has been investigated. A new lipophilic binding pocket in human histamine H1 receptor has been identified. The first atom-level model of human histamine H4 receptor has been constructed by ligand supported homology modelling. that was used to develop an effective virtual screening protocol. The protocol allowed us to perform the largest structure based virtual screening experiment using a screening database of more than 8 million compounds. Identified new chemical scaffolds showed submicromolar binding affinity towards the human histamine H4 receptor as revealed by experimental studies
Phosphorylation adjacent to the nuclear localization signal of human dUTPase abolishes nuclear import: Structural and mechanistic insights
Phosphorylation adjacent to nuclear localization signals (NLSs) is involved in the regulation of nucleocytoplasmic transport. The nuclear isoform of human dUTPase, an enzyme that is essential for genomic integrity, has been shown to be phosphorylated on a serine residue (Ser11) in the vicinity of its nuclear localization signal; however, the effect of this phosphorylation is not yet known. To investigate this issue, an integrated set of structural, molecular and cell biological methods were employed. It is shown that NLS-adjacent phosphorylation of dUTPase occurs during the M phase of the cell cycle. Comparison of the cellular distribution of wild-type dUTPase with those of hyperphosphorylation- and hypophosphorylation-mimicking mutants suggests that phosphorylation at Ser11 leads to the exclusion of dUTPase from the nucleus. Isothermal titration microcalorimetry and additional independent biophysical techniques show that the interaction between dUTPase and importin-alpha, the karyopherin molecule responsible for 'classical' NLS binding, is weakened significantly in the case of the S11E hyperphosphorylation-mimicking mutant. The structures of the importin-alpha-wild-type and the importin-alpha-hyperphosphorylation-mimicking dUTPase NLS complexes provide structural insights into the molecular details of this regulation. The data indicate that the posttranslational modification of dUTPase during the cell cycle may modulate the nuclear availability of this enzyme