Ultra-high resolution X-ray structure of orthorhombic bovine pancreatic Ribonuclease A at 100K.

The crystal structure of orthorhombic Bovine Pancreatic Ribonuclease A has been determined to 0.85 Å resolution using low temperature, 100 K, synchrotron X-ray data collected at 16000 keV (λ = 0.77 Å).

Semi-Synthetic Analogues of Cryptolepine as a Potential Source of Sustainable Drugs for the Treatment of Malaria, Human African Trypanosomiasis, and Cancer.

The prospect of eradicating malaria continues to be challenging in the face of increasing parasite resistance to antimalarial drugs so that novel antimalarials active against asexual, sexual, and liver-stage malaria parasites are urgently needed. In addition, new antimalarials need to be affordable and available to those most in need and, bearing in mind climate change, should ideally be sustainable. The West African climbing shrub is used traditionally for the treatment of malaria; its principal alkaloid, cryptolepine (), has been shown to have antimalarial properties, and the synthetic analogue 2,7-dibromocryptolepine () is of interest as a lead toward new antimalarial agents.

Specific refolding pathway of viscumin A chain in membrane-like medium reveals a possible mechanism of toxin entry into cell.

How is a water-soluble globular protein able to spontaneously cross a cellular membrane? It is commonly accepted that it undergoes significant structural rearrangements on the lipid-water interface, thus acquiring membrane binding and penetration ability. In this study molecular dynamics (MD) simulations have been used to explore large-scale conformational changes of the globular viscumin A chain in a complex environment - comprising urea and chloroform/methanol (CHCl/MeOH) mixture. Being well-packed in aqueous solution, viscumin A undergoes global structural rearrangements in both organic media.

Ultra-high resolution X-ray structures of two forms of human recombinant insulin at 100 K.

The crystal structure of a commercially available form of human recombinant (HR) insulin, Insugen (I), used in the treatment of diabetes has been determined to 0.92 Å resolution using low temperature, 100 K, synchrotron X-ray data collected at 16,000 keV (λ = 0.77 Å).

X-ray structures of two forms of the antibiotic oligomycin A: an inhibitor of ATP synthase.

Background: Corrections to the chemical and x-ray structures of two forms of the antibiotic oligomycin A are presented: the original and best known, form (E), from Streptomyces diastatochromogenes, and a new form (C) from Streptomyces diastaticus.

Method: The crystal structures are isomorphous, crystallizing in space group P212121, with Z = 4[C45H73O11.CH3OH] per unit cell.

A comparative study of the single crystal X-ray determination and molecular modelling of the binding of oligomycin to ATP synthase.

Recently published X-ray structures of three common forms, A, B and C, of oligomycin, including absolute configurations, are investigated to examine their binding to ATP Synthase. The X-ray studies reveal regions with differences in three-dimensional structure and hydrogen bonding propensity between the oligomycins, which may be associated with their potential to bind to sites on ATP Synthase. Computational docking studies carried out using MOE with the X-ray structures and an homology model of the F(O) domain of ATP Synthase from Escherichia coli, are used to derive an induced fit pocket.

Structural basis for sugar recognition, including the Tn carcinoma antigen, by the lectin SNA-II from Sambucus nigra.

Bark of elderberry (Sambucus nigra) contains a galactose (Gal)/N-acetylgalactosamine (GalNAc)-specific lectin (SNA-II) corresponding to slightly truncated B-chains of a genuine Type-II ribosome-inactivating protein (Type-II RIPs, SNA-V), found in the same species. The three-dimensional X-ray structure of SNA-II has been determined in two distinct crystal forms, hexagonal and tetragonal, at 1.90 A and 1.

Antagonist binding in the rat muscarinic receptor A study by docking and X-ray crystallography.

A series of agonists to the rat muscarinic receptor have been docked computationally to the active site of a homology model of rat M1 muscarinic receptor. The agonists were modelled on the X-ray crystal structure of atropine, which is reported here and the docking studies are shown to reproduce correctly the order of experimental binding affinities for the agonists as well as indicate where there appear to be inconsistencies in the experimental data. The crystal and molecular structure of atropine (tropine tropate; alpha-[hydroxymethyl]benzeneacetic acid 8-methyl[3.

A new gene encoding the ribosome-inactivating protein from mistletoe extracts.

Extracts from mistletoe (Viscum album L.) contain three main toxic proteins--the lectins MLI (also known as viscumin), MLII and MLIII. A catalytic subunit of the mistletoe plant toxic lectin MLIII has been cloned and expressed in Escherichia coli cells.

Two new cyclosporin folds observed in the structures of the immunosuppressant cyclosporin G and the formyl peptide receptor antagonist cyclosporin H at ultra-high resolution.

Cyclosporins are cyclic undecapeptides of fungal origin the best known of which, CsA, is a lead clinical immunosuppressant; CsG is a potential clinical immunosuppressant differing from CsA in residue 2 (L-alpha-amino-butyric acid in CsA, L-norvaline in CsG); and CsH is an inverse formyl peptide receptor agonist, differing from CsA in the chiral inversion of MeVal-11 from L to D. Crystal structure determinations of CsG and CsH were undertaken to identify structural and surface features important for biological activity and the future design of new cyclosporin derivatives. Ultra-high resolution X-ray structures (0.

Crystal structure at 3 A of mistletoe lectin I, a dimeric type-II ribosome-inactivating protein, complexed with galactose.

The X-ray structure of mistletoe lectin I (MLI), a type-II ribosome-inactivating protein (RIP), cocrystallized with galactose is described. The model was refined at 3.0 A resolution to an R-factor of 19.