Protein and Peptide Letters - Volume 12, Issue 6, 2005

Scientists from over 20 major research centers recently convened to discuss advances and new discoveries in “Protein MisFolding and MisProcessing in Disease.” Understanding protein mechanisms the underlying etiology of complex diseases lies in analyzing the associated biochemical mechanisms, which include folding patterns, processing patterns, chaperone regulators, stress pathways, and signal transduction.

Most spider antimicrobial peptides share a common mechanism of membrane permeabilisation and the innate immune systems of the pathogen. In this review, we present recent accounts of the application at the preclinical level that should be tried and the range of bioactivities and their particular structure can be harnessed for molecular engineering applications and in drug design. Structural analyses such as amino acid Read More

The Aβ peptide has been identified as central to the onset and development of Alzheimer's disease (AD) and several hypotheses about toxicity involving Aβ peptides have been proposed including mechanisms of oxidative stress and disruption of calcium homeostasis. The biology, structure and physical properties of Aβ peptides are discussed, as well as existing therapeutics and future strategies for the treatment of AD.

The Trypanosoma cruzi ribosomal P0 protein (TcP0) is part of the ribosomal stalk, which is an elongated lateral protuberance of the large ribosomal subunit involved in the translocation step of protein synthesis. The TcP0 Cterminal peptide is highly antigenic and a major target of the antibody response in patients with systemic lupus erythematosus and patients suffering chronic heart disease produced by Trypanosoma cruzi inf Read More

The Kruppel-associated box (KRAB) domain is a potent transcription repression bipartite domain, shared by over 400 zinc finger proteins in humans, involved in the regulation of many functions. KRAB domains are both physically and functionally bipartite (A and B modules). The lone KRAB-A and composite KRAB-AB domains from the human ZNF2 protein were over-expressed as recombinant proteins in E. coli, isolated and purifie Read More

Aspergillus sp. phytase contains five disulfide bonds. In order to elucidate their role, the reactivation and refolding of phytase in the absence and presence of dithiothreitol (DTT) was investigated. The results indicated that the disulfide bonds play an important role in the catalytic activity and conformational stability of the enzyme.

The Coxsackievirus and Adenovirus receptor (CAR) mediates entry of coxsackievirus and adenovirus. CAR possesses an extracellular region that is comprised of 2 Ig domains termed CAR-D1 and CAR-D2. The 1H, 13C and 15N resonances of CAR-D2 have been assigned and the secondary structure has been deduced.

From the experimentally defined rate of heterogeneous formation of protein crystals and number of collisions between protein molecules with substrate, the energy barrier for adhesion of protein molecule to alien materials is estimated. According to the Boltzmann equation for energy distribution this barrier is of the order of 10 -12 erg per molecule.

Glucose isomerase (D-xylose ketol-isomerase, EC 5.3.1.5.) catalyses the isomerization reaction of glucose and xylose. The small angle X-ray scattering (SAXS) data of glucose/xylose isomerase from Streptomyces rubiginosus were recorded for protein solution using synchrotron radiation. The experimental data were compared with theoretical scattering calculated on the basis of the known crystal structure (PDB code: 1OA Read More

Studies of the human defensins have been hampered by the lack of a simple expression system allowing for rapid production of functional peptide forms. Here, we describe a Saccharomyces cerevisiae AH22 expression system that meets that condition. The 42 amino acid form of human β-defensin-1 was expressed under the control of the ADH1 promoter. The optimum conditions for expression were determined and the sta Read More

Despite recent progress in the structural and functional analysis of bacterial and archaeal ribosomes, the structure and biogenesis of eukaryotic ribosomes still awaits a detailed characterization. Ribosomal protein-specific antibodies would be valuable tools for such studies, but their production is commonly hindered by the poor expression and solubility of eukaryotic ribosomal proteins in E. coli. We report here an imp Read More

Several pests are capable of decreasing crop production causing severe economical and social losses. Aiming to find novel molecules that could impede the digestion process of different pests, a screening of a-amylase and trypsin-like proteinase inhibitors was carried out in Prosopis juliflora, showing the presence of both in dry seeds. Furthermore, a novel trypsin inhibitor, with molecular mass of 13,292 Da, was purified showi Read More

Metallothionein (MT) is the protein that has been shown to bind heavy metals, scavenge free radicals, protect DNA from radiation damage, and alleviate disease symptoms. However, only very limited success has been achieved in expression and production of active recombinant metallothionein. In this study, human metallothionein 1A (hMT1A) was transformed into yeast Pichia pastoris for expression with secretio Read More

Photosystem II (PSII) is a multisubunit chlorophyll-binding enzyme that absorbs light to catalyze water oxidation and plastoquinone reduction. Chlorophyll excitonic interaction changes in PSII were studied by absorption and circular dichroism spectra from 25°C to 80°C, and protein subunit denaturation was monitored by differential scanning calorimetry. A four-stage process of chlorophyll excitonic interaction change was ob Read More

The use of Nα-tert.-butyloxycarbonyl-Nπ-benzyloxymethylhistidine [Boc-His(Bom)] in peptide synthesis results in a serious level of side products arising from the generation of formaldehyde during the HF cleavage reaction. In particular, when treating a His(Bom)-containing peptide having Cys at the N-terminus by HF, this leads to almost complete conversion of the Cys-peptide to thiazolidyl (Thz)-peptide unless precautions Read More

A 6.5 kDa serine protease inhibitor was purified by anion-exchange chromatography from the crude extract of the Inga umbratica seeds, containing inhibitor isoforms ranging from 6.3 to 6.7 kDa and protease inhibitors of ∼19 kDa. The purified protein was characterized as a potent inhibitor against trypsin and chymotrypsin and it was named I. umbratica trypsin and chymotrypsin inhibitor (IUTCI). MALDI-TOF spectra Read More

Two mannose/glucose specific seed lectins were isolated from Parkia biglandulosa and Parkia roxburghii and were characterized w.r.t various physicochemical properties. Unlike other Parkia lectins a comparison of native and subunit molecular mass showed that both Parkia lectins were heterotetramers. Parkia biglandulosa lectin was found to be T-cell mitogen as revealed by IL-2 bioassay. These lectins showed anti-prolif Read More

Isozymes of yeast alcohol dehydrogenase are slowly denatured at moderate hydrostatic pressures (<3 kbar). The time courses for inactivation are biphasic and both phases of both isozymes are protected by trehalose. ADH-I is slightly more barostable than ADH-II which is opposite to their thermostabilities. Trehalose at 1M extends their halflives about 6-fold at 2 kbar, pH 7.5 and 25°C. In contrast, 1M sucrose provides only 4 Read More

An innovative type of multifunctional helicoid artificial carriers, formed by the repetitive Lys-Aib-Gly (SOCn- I) or by the Aib-Lys-Aib-Gly (SOC n-II), with structural rigidity and regularity were successfully applied in our laboratory for anchoring antigenic/immunogenic peptides. The carriers, designed to display a predetermined 3D structure, adopt the 3 10 helical conformation, while the attached peptides preserve their origin Read More

Centrins are four-EF-hand Ca2+-binding proteins, which belong to the CaM super family. The centrin from ciliate Euplotes Octocarinatus has been expressed in Escherichia coli, purified and crystallized using the hanging-drop method. Rod-like crystals were grown and diffracted to 2.0 Å. The crystals belong to space group P222 and the unit-cell parameters are a=34.442 Å, b=48.954 Å, c=72.583 Å.