[en] The optimal characteristics which radiopharmaceuticals need to possess are presented in literature. The visualisation of inside organic structure is possible by use of adequate radio pharmaceutic and harmless methods. In aim of preparation of 'ideal' pharmacy, which made possible obtaining of good scintiphotos with the smallest possible radiation effect, a great number of organic and inorganic ligands are labeled in Laboratory of radioisotope. (author)

[en] The specific structural features of technetium mononuclear octahedral oxo complexes have been considered. The structures of d²-Tc(V) mono- and dioxo complexes, d²-Tc(V) pseudodioxo compounds (Tc(V) mono-oxo complexes with an additional multiply bonded RO⁻ ligand), and d⁰-Tc(VII) trioxo compounds are analyzed.

No abstract available

[en] G protein coupled receptors (GPCRs) are seven helical transmembrane proteins that function as signal transducers. They bind ligands in their extracellular and transmembrane regions and activate cognate G proteins at their intracellular surface at the other side of the membrane. The relay of allosteric communication between the ligand binding site and the distant G protein binding site is poorly understood. In this study, GREMLIN, a recently developed method that identifies networks of co-evolving residues from multiple sequence alignments, was used to identify those that may be involved in communicating the activation signal across the membrane. The GREMLIN-predicted long-range interactions between amino acids were analyzed with respect to the seven GPCR structures that have been crystallized at the time this study was undertaken. We demonstrate the use of GREMLIN to reveal a network of statistically correlated and functionally important residues in class A GPCRs. GREMLIN identified that ligand binding pocket residues are extensively correlated with distal residues. An analysis of the GREMLIN edges across multiple structures suggests that there may be a minimal binding pocket common to the seven known GPCRs. Further, the activation of rhodopsin involves these long-range interactions between extracellular and intracellular domain residues mediated by the retinal domain.

[en] LigSearch is a web server for identifying ligands likely to bind to a given protein. Identifying which ligands might bind to a protein before crystallization trials could provide a significant saving in time and resources. LigSearch, a web server aimed at predicting ligands that might bind to and stabilize a given protein, has been developed. Using a protein sequence and/or structure, the system searches against a variety of databases, combining available knowledge, and provides a clustered and ranked output of possible ligands. LigSearch can be accessed at http://www.ebi.ac.uk/thornton-srv/databases/LigSearch

[en] The present work introduces synthesis, structure and spectroscopic properties of novel water soluble dicationic binuclear Au(I) complex [Au₂L₂]²⁺ with bridge P,P-coordination, where L is cyclic PNNP ligand 1,5-bis(p-tolyl)−3,7-bis(pyridine-2-yl)−1,5-diaza-3,7-diphosphacyclooctane. Its ion-pairing with anionic hexarhenium cluster complexes ([{Re₆S₈}(OH)₆]^4- and [{Re₆S₈}(CN)₆]^4-) is represented herein as a reason for bottom-up design of supramolecular heterometallic assemblies with the enhanced cluster-centered luminescence and heterometallic colloids with high luminescence response to acidification in the range of pH 6.0-5.5.

[en] Recent studies demonstrate the important roles of surface ligands in creating metal-organic interfaces that can significantly improve both catalytic activity as well as selectivity of chemically synthetized nanoparticle (NP) catalysts. Both steric and electronic effects can be efficiently used to tune catalytic properties of the NPs. Here, we overview the recent advancements in the field of the surface science of NPs for their catalytic applications and discuss the steric and electronic effects of ligands immobilized at the NP surface on the activity and selectivity of catalytically active NPs in different catalytic reactions.

[en] NE1406, the first structural representative of PF09410, reveals a lipocalin-like fold with features that suggest involvement in lipid metabolism. In addition, NE1406 provides potential structural templates for two other protein families (PF07143 and PF08622). The first structural representative of the domain of unknown function DUF2006 family, also known as Pfam family PF09410, comprises a lipocalin-like fold with domain duplication. The finding of the calycin signature in the N-terminal domain, combined with remote sequence similarity to two other protein families (PF07143 and PF08622) implicated in isoprenoid metabolism and the oxidative stress response, support an involvement in lipid metabolism. Clusters of conserved residues that interact with ligand mimetics suggest that the binding and regulation sites map to the N-terminal domain and to the interdomain interface, respectively

[en] As part of our project to develop small size, neutral, mixed ligand oxotechnetium and oxorhenium complexes of the general formula MOL₁L₂, we have synthesized and characterized four novel complexes of general formula MO[EtN(CH₂CH₂S)₂][p-O₂N-C₆H₄S] and MO [(Et₂NCH₂CH₂NCH₂CH₂S)(p-O₂N-C₆H₄S)] where M=Re (complex 1 and complex 2) or M=Tc (complex 3 and complex 4) as a new approach for hypoxia or ischemic tissue organ imaging. Complex 1 and 2 have been synthesized by exchange reaction in equimolar quantities of the tridentate and the monodentate ligand on ReOC1₃(PPh₃). Only the syn isomer have been isolated and characterized by elemental analysis, IR, UV-vis, and ¹H NMR. Crystal datas reveal a trigonal bipyramidal geometry around the metal for complex 1 and square pyramidal geometry around the metal for complex 2. Complex 3 is prepared by exchange reaction using Tc-99m-glucoheptonate as precursor and equimolar quantities of two ligands; EtN(CH₂CH₂SH)₂ and p-O₂N-C₆H₄SH while complex 4 is prepared by simultaneously reacting the Et₂NCH₂CH₂NHCH₂CH₂SH and p-O₂N-C₆H₄SH ligands with the ⁹⁹Tc gluconate precursor in equimolar amount in MeOH. It may be concluded that the result of SNS/S and SNN/S mixed ligand of oxotechnetium is comfirmed by comparative HPLC studies with complex 1 and complex 2, since rhenium is a surrogate of technetium

[en] The kinetic studies on the reactions of dipropyl chlorophosphate (3O) with substituted anilines (XC₆H₄NH₂) and deuterated anilines (XC₆H₄ND₂) have been carried out in acetonitrile at 55.0 .deg. C. The obtained deuterium kinetic isotope effects (DKIEs: k_H/k_D) are primary normal (k_H/k_D = 1.09-1.01) with the strongly basic anilines while secondary inverse (k_H/k_D = 0.74-0.82) with the weakly basic anilines. The steric effects of the two ligands on the rates are extensively discussed for the anilinolyses of the (R1O)(R2O)P(=O or S)Cl-type chlorophosphates and chlorothiophosphates. A concerted mechanism is proposed with a frontside nucleophilic attack involving a hydrogen-bonded four-center-type transition state for the strongly basic anilines and with a backside attack transition state for the weakly basic anilines on the basis of the DKIEs, primary normal and secondary inverse with the strongly and weakly basic anilines, respectively