Crystallization and Preliminary X-ray Studies of the Basic Lectin from Winged Bean (Psophocarpus tetragonolobus)

The basic lectin from winged bean (Psophocarpus tetragonolobus) could be crystallized using polyethyleneglycol (PEG) 4000 (I), PEG 8000 (II) and 2-methylpentane-2,4-diol (MPD) (III) as precipitants. Crystal forms I and II grew in the presence of methyl-α-Image -galactopyranoside or N -acetylgalactosamine while III grew in the absence of sugar. The three forms have the same space group (P21212) and similar unit cell dimensions with two dimeric molecules in the asymmetric unit. The unit cell dimensions are a = 156·8 Å, b = 89·0 Å, c = 73·3 Å for I, a = 155·5 Å, b = 92·3 Å, c = 72·5 Å for II and a = 148·3 Å, b = 90·7 Å, c = 73·8 Å for III. The crystals, particularly those grown using PEG 8000, are suitable for high resolution X-ray analysis, which is in progress.

A preliminary survey of dermatomycoses in Bangalore

Clinical and mycological investigations were made on 225 cases of suspected dermatomycoses. Of these, 102 were microscopically positive. But only 63 were culturally positive, and these are analysed here with regard to clinical patterns and aetiological species, age, sex and occupational incidence and susceptibility to griseofulvin in vitro. As in most other parts of India, Trichophyton rubrum was the dominant species. A high proportion of Epidermophyton floccosum was an unusual feature seen. Of the clinical types, tinea cruris was the most common. The isolates were sensitive to griseofulvin at low concentrations of 1 to 5 μg per ml of agar medium, E. floccosum being the most sensitive.

Cloning, expression, purification, crystallization and preliminary X-ray crystallographic study of the putative SAICAR synthetase (PH0239) from Pyrococcus horikoshii OT3

The study of proteins involved in de novo biosynthesis of purine nucleotides is central in the development of antibiotics and anticancer drugs. In view of this, a protein from the hyperthermophile Pyrococcus horikoshii OT3 was isolated, purified and crystallized using the microbatch method. Its primary structure was found to be similar to that of SAICAR synthetase, which catalyses the seventh step of de novo purine biosynthesis. A diffraction-quality crystal was obtained using Hampton Research Crystal Screen II condition No. 34, consisting of 0.05 M cadmium sulfate hydrate, 0.1 M HEPES buffer pH 7.5 and 1.0 M sodium acetate trihydrate, with 40%(v/v) 1,4-butanediol as an additive. The crystal belonged to space group P3(1), with unit-cell parameters a = b = 95.62, c = 149.13 angstrom. Assuming the presence of a hexamer in the asymmetric unit resulted in a Matthews coefficient (V-M) of 2.3 angstrom(3) Da(-1), corresponding to a solvent content of about 46%. A detailed study of this protein will yield insights into structural stability at high temperatures and should be highly relevant to the development of antibiotics and anticancer drugs targeting the biosynthesis of purine nucleotides.

Crystallization and preliminary X-ray crystallographic analysis of a galactose-specific lectin from Dolichos lablab

The galactose-specific lectin from the seeds of Dolichos lablab has been crystallized using the hanging-drop vapour-diffusion technique. The crystals belong to space group P1, with unit-cell parameters a = 73.99, b = 84.13, c = 93.15 angstrom, alpha = 89.92, beta = 76.01, gamma = 76.99 degrees. X-ray diffraction data to a resolution of 3.0 angstrom have been collected under cryoconditions ( 100 K) using a MAR imaging-plate detector system mounted on a rotating-anode X-ray generator. Molecular-replacement calculations carried out using the available structures of legume lectins as search models revealed that the galactose-specific lectin from D. lablab forms a tetramer similar to soybean agglutinin; two such tetramers are present in the asymmetric unit.

Crystallization and preliminary X-ray studies of a galactose-specific lectin from the seeds of bitter gourd (Momordica charantia)

A galactose-specific lectin from the seeds of bitter gourd (Momordica charantia) is a four-chain type II ribosome-inactivating protein (RIP) resulting from covalent association through a disulfide bridge between two identical copies of a two-chain unit. The available structural information on such four-chain RIPs is meagre. The bitter gourd lectin was therefore crystallized for structural investigation and the crystals have been characterized. It is anticipated that the structure of the orthorhombic crystals will be analysed using molecular replacement by taking advantage of its sequence, and presumably structural, homology to normal two-chain type II RIPs.

Crystallization and preliminary X-ray studies of the C-terminal domain of Mycobacterium tuberculosis LexA

The C-terminal domain of Mycobacterium tuberculosis LexA has been crystallized in two different forms. The form 1 and form 2 crystals belonged to space groups P3(1)21 and P3(1), respectively. Form 1 contains one domain in the asymmetric unit, while form 2 contains six crystallographically independent domains. The structures have been solved by molecular replacement.

Legal Reasoning in Context

This study in EU law analyses the reasoning of the Court of Justice (the Court of Justice of the European Union) in a set of its preliminary rulings. Preliminary rulings are answers to national courts questions on the interpretation (and validity) of EU law called preliminary references. These questions concern specific legal issues that have arisen in legal disputes before the national courts. The Court of Justice alone has the ultimate authority to interpret EU law. The preliminary rulings bind the national courts in the cases giving rise to the preliminary reference, and the interpretations of EU law offered in the preliminary rulings are considered generally binding on all instances applying EU law. EU law is often described as a dynamic legal order and the Court of Justice as at the vanguard of developing it. It is generally assumed that the Court of Justice is striving to realise the EU s meta-level purpose (telos): integration. Against this backdrop one can understand the criticism the Court of Justice is often faced with in certain fields of EU law that can be described as developing. This criticism concerns the Court s (negatively) activist way of not just stating the law but developing or even making law. It is difficult to analyse or prove wrong this accusation as it is not in methodological terms clearly established what constitutes judicial activism, or more exactly where the threshold of negative activism lies. Moreover, one popular approach to assessing the role of the Court of Justice described as integration through law has become fairly political, neglecting to take into consideration the special nature of law as both facilitating and constraining action, not merely a medium for furthering integration. This study offers a legal reasoning approach of a more legalist nature, in order to balance the existing mix of approaches to explaining what the Court of Justice does and how. Reliance on legal reasoning is found to offer a working framework for analysis, whereas the tools for an analysis based on activism are found lacking. The legal reasoning approach enables one to assess whether or not the Court of Justice is pertaining to its own established criteria of interpretation of EU law, and if it is not, one should look more in detail at how the interpretation fits with earlier case-law and doctrines of EU law. This study examines the reasoning of the Court of Justice in a set of objectively chosen cases. The emphasis of the study is on analysing how the Court of Justice applies the established criteria of interpretation it has assumed for itself. Moreover, the judgments are assessed not only in terms of reasoning but also for meaningful silences they contain. The analysis is furthermore contextualised by taking into consideration how the cases were commented by legal scholars, their substantive EU law context, and also their larger politico-historical context. In this study, the analysis largely shows that the Court of Justice is interpreting EU law in accordance with its previous practice. Its reasoning retains connection with the linguistic or semiotic criteria of interpretation, while emphasis lies on systemic reasoning. Moreover, although there are a few judgments where the Court of Justice offers clearly dynamic reasoning or what can be considered as substantive reasoning stemming from, for example, common sense or reasonableness, such reasons are most often given in addition to systemic ones. In this sense and even when considered in its broader context, the case-law analysed in this study does not portray a specifically activist image of the Court of Justice. The legal reasoning approach is a valid alternative for explaining how and why the Court of Justice interprets EU law as it does.

Cloning, expression, purification and preliminary X-ray crystallographic studies of 2-methylisocitrate lyase from Salmonella typhimurium. Acta Crystallogr

In Salmonella typhimurium, propionate is oxidized to pyruvate via the 2-methylcitric acid cycle. The last step of this cycle, the cleavage of 2-methylisocitrate to succinate and pyruvate, is catalysed by 2-methylisocitrate lyase (EC 4.1.3.30). Methylisocitrate lyase (molecular weight 32 kDa) with a C-terminal polyhistidine affinity tag has been cloned and overexpressed in Escherichia coli and purified and crystallized under different conditions using the hanging-drop vapour-diffusion technique. Crystals belong to the orthogonal space group P2(1)2(1)2(1), with unit-cell parameters a = 63.600, b = 100.670, c = 204.745 Angstrom. A complete data set to 2.5 Angstrom resolution has been collected using an image-plate detector system mounted on a rotating-anode X-ray generator.

Cloning, expression, purification, crystallization and preliminary X-ray studies of a secreted lectin (Rv1419) from Mycobacterium tuberculosis

A secreted lectin, Rv1419, from Mycobacterium tuberculosis has been cloned, expressed, purified and crystallized and the crystals have been characterized. This represents the first X-ray investigation of a lectin or lectin-like molecule from the pathogen. The cubic crystals contain one molecule in the asymmetric unit. Sequence comparisons indicate that the lectin has a beta-trefoil fold and belongs to a well characterized family of carbohydrate-binding modules. Structural analysis of the crystals is in progress.