Crystallization and preliminary X-ray study of haem-binding protein from the bloodsucking insect Rhodnius prolixus.

Rhodnius haem-binding protein (RHBP) from the bloodsucking insect Rhodnius prolixus, a 15 kDa protein, has been crystallized using polyethylene glycol as a precipitant. X-ray diffraction data have been collected at a synchrotron source. The crystals belong to the space group P4(1(3))2(1)2, with unit-cell parameters a = b = 64.

Crystal structures of bovine beta-lactoglobulin in the orthorhombic space group C222(1). Structural differences between genetic variants A and B and features of the Tanford transition.

The crystal structures of beta-lactoglobulin genetic variants A and B have been determined in the orthorhombic space group C222(1) (lattice Y) by X-ray diffraction at 2.0 A and 1.95 A resolution, respectively.

Structural basis for low catalytic activity in Lys49 phospholipases A2--a hypothesis: the crystal structure of piratoxin II complexed to fatty acid.

Asp49 plays a fundamental role in supporting catalysis by phospholipases A2 by coordinating the calcium ion which aids in the stabilization of the tetrahedral intermediate. In several myotoxins from the venoms of Viperidae snakes, this aspartic acid is substituted by lysine. The loss of calcium binding capacity by these mutants has become regarded as the standard explanation for their greatly reduced or nonexistent phospholipolytic activity.

Three-dimensional structure of the Fab from a human IgM cold agglutinin.

Cold agglutinins (CAs) are IgM autoantibodies characterized by their ability to agglutinate in vitro RBC at low temperatures. These autoantibodies cause hemolytic anemia in patients with CA disease. Many diverse Ags are recognized by CAs, most frequently those belonging to the I/i system.

Purification, crystallization and preliminary diffraction study of beta-galactosidase from Penicillium sp.

Crystals of an extracellular beta-galactosidase from Penicillium sp. (MW = 120 +/- 5 kDa) have been obtained from a sodium phosphate buffer using PEG as precipitant. The crystals belong to the tetragonal space group P4(1)or P4(3), with unit-cell parameters a = b = 110.

Preliminary X-ray diffraction studies of rabbit muscle triose phosphate isomerase (TIM).

Triose phosphate isomerase (TIM) is responsible for the interconversion between GAP and DHAP in the glycolytic pathway. Two crystal forms belonging to space group P2(1)2(1)2(1) were obtained by the hanging-drop method and were designated A and B. Synchrotron X-ray diffraction data were collected for both forms.

Purification, crystallization and preliminary X-ray study of beta-xylosidase from Trichoderma reesei.

An extracellular multifunctional beta-xylosidase was purified from a culture of the fungus Trichoderma reesei. The active 95 +/- 5 kDa enzyme has been crystallized from sodium acetate buffer using PEG as a precipitant. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 67.

Amino acid sequence of piratoxin-II, a myotoxic lys49 phospholipase A(2) homologue from Bothrops pirajai venom.

The complete amino acid sequence of the 121 amino acid residues of piratoxin II, a phospholipase A(2) like myotoxin from Bothrops pirajai venom, is reported. PrTX-II is a basic protein with a molecular mass of 13740 Da, a calculated pI of 9.03, but an experimental pI of 8.

Divergence in macromolecular assembly: X-ray crystallographic structure analysis of lumazine synthase from Brucella abortus.

We have determined the three-dimensional structure of 6, 7-dimethyl-8-ribityllumazine synthase (lumazine synthase) from Brucella abortus, the infectious organism of the disease brucellosis in animals. This enzyme catalyses the formation of 6, 7-dimethyl-8-ribityllumazine, the penultimate product in the synthesis of riboflavin. The three-dimensional X-ray crystal structure of the enzyme from B.

Pressure denaturation of beta-lactoglobulin. Different stabilities of isoforms A and B, and an investigation of the Tanford transition.

Beta-lactoglobulin, the main whey protein in bovine milk, exists in several isoforms of which the most abundant are isoforms A and B. We have previously reported the denaturation of beta-lactoglobulin A by hydrostatic pressure [Valente-Mesquita, V.L.

The high resolution crystal structure of yeast hexokinase PII with the correct primary sequence provides new insights into its mechanism of action.

Hexokinase is the first enzyme in the glycolytic pathway, catalyzing the transfer of a phosphoryl group from ATP to glucose to form glucose 6-phosphate and ADP. Two yeast hexokinase isozymes are known, namely PI and PII. The crystal structure of yeast hexokinase PII from Saccharomyces cerevisiae without substrate or competitive inhibitor is determined and refined in a tetragonal crystal form at 2.

Stability of L-asparaginase: an enzyme used in leukemia treatment.

L-asparaginase from Escherichia coli is an important enzyme widely used in leukemia treatment under the trade name Elspar. Up to now, however, the aspects of its stability and storage has not been studied in detail. The aim of this work is to analyze the factors that could interfere in the enzyme's stability.

Crystallization and preliminary X-ray study of beta--mannosidase from Trichoderma reesei.

beta-Mannosidase from Trichoderma reesei, a 105 kDa glycoprotein, has been crystallized. The crystals belong to the space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell dimensions a = b = 165.86, c = 122.

Crystallization and preliminary X-ray diffraction analysis of the catalytic subunit of ADP-glucose pyrophosphorylase from potato tuber.

ADP-glucose pyrophosphorylase is the key regulatory enzyme in the biosynthesis of starch in plants and glycogen in bacteria. The enzyme from potato tuber is comprised of a regulatory subunit and a catalytic subunit and is present as a heterotetramer (alpha(2)beta(2)). The catalytic subunit from potato tuber (50 kDa) was crystallized in four different forms, two of which are suitable for structural studies.

Crystallization and preliminary crystal analysis of yeast hexokinase PI and PII.

Hexokinase is the prime enzyme of the Embden-Meyerhof pathway and is responsible for the first stage of energy conversion. It catalyzes the transfer of a phosphate to glucose to form glucose-6-phosphate. Yeast hexokinase PII is also known to play an important role in glucose signal transduction.

Preparation and preliminary X-ray diffraction studies of a new crystal form of L-asparaginase from Escherichia coli.

L-Asparaginase is an enzyme which hydrolyzes asparagine to produce aspartic acid and ammonia. It is an effective chemotherapeutic drug, especially in the treatment of acute lymphoblastic leukaemia in children. The enzyme from Escherichia coli was crystallized in a new crystal form with space group C2, unit-cell parameters a = 76.

Crystallization and preliminary X-ray diffraction studies of human catalase.

The enzyme catalase (H(2)O(2)-H(2)O(2) oxidoredutase; E.C. 11.

Purification, crystallization and preliminary crystallographic study of a Kunitz-type trypsin inhibitor from Delonix regia seeds.

The Kunitz-type trypsin inhibitor from seeds of Flamboyant (Delonix regia) has been purified to homogeneity and plate-like crystals suitable for X-ray analysis have been grown by the hanging-drop method using PEG 6000 as a precipitant. The crystals belong to space group P2(1)2(1)2(1) with unit-cell parameters a = 32.15, b = 69.

Crystallization and preliminary diffraction studies of a recombinant major urinary protein.

A monoclinic crystal form of a recombinant major urinary protein, (MUP) from mouse, has been obtained. MUP is a member of the lipocalin family whose biological function relates to olfaction and sexual communication. Crystals were grown by the vapour-diffusion technique against a mother liquor containing CdCl2.

Crystal structure of neurotoxin Ts1 from Tityus serrulatus provides insights into the specificity and toxicity of scorpion toxins.

The crystal structure of neurotoxin Ts1, a major component of the venom of the Brazilian scorpion Tityus serrulatus, has been determined at 1.7 A resolution. It is the first X-ray structure of a highly toxic anti-mammalian beta-toxin.

The two types of 3-dehydroquinase have distinct structures but catalyze the same overall reaction.

The structures of enzymes catalyzing the reactions in central metabolic pathways are generally well conserved as are their catalytic mechanisms. The two types of 3-dehydroquinate dehydratase (DHQase) are therefore most unusual since they are unrelated at the sequence level and they utilize completely different mechanisms to catalyze the same overall reaction. The type I enzymes catalyze a cis-dehydration of 3-dehydroquinate via a covalent imine intermediate, while the type II enzymes catalyze a trans-dehydration via an enolate intermediate.

Crystallization and preliminary X-ray diffraction studies of piratoxin III, a D-49 phospholipase A2 from the venom of Bothrops pirajai.

Piratoxin III (PrTX-III) is a phospholipase A2 (PLA2, E.C. 3.

Crystallization and preliminary diffraction data of neurotoxin Ts-gamma from the venom of the scorpion Tityus serrulatus.

Scorpion neurotoxin Ts-gamma was isolated from Tityus serrulatus venom and purified to apparent homogeneity by ion-exchange HPLC. Crystals of the toxin were grown using polyethylene glycol 6000 as precipitant and were found to belong to the monoclinic space group P21 with cell parameters a = 22.20, b = 36.

Crystallization and preliminary X-ray diffraction studies of piratoxin II, a phospholipase A2 isolated from the venom of Bothrops pirajai.

The phospholipases A2 (PLA2, E.C. 3.

Crystallization and preliminary x-ray diffraction analysis of the lumazine synthase from Brucella abortus.

Lumazine synthase from Brucella abortus was overexpressed in Escherichia coli, refolded, and purified to apparent homogeneity. Crystals of lumazine synthase were grown by the hanging drop vapor diffusion method using polyethylene glycol 8000 or ammonium sulfate as precipitants. They belong to the trigonal space group P321 with cell parameters a = b = 132.