Search

Macrocyclic compounds meso-(p-acetamidophenyl)-calix[4]pyrrole and meso-(m-acetamidophenyl)-calix[4]pyrrole have previously been reported to exhibit cytotoxic properties towards lung cancer cells. Here, we report pre-clinical in vitro and in vivo studies showing that these calixpyrrole derivatives can inhibit cell growth in both PC3 and DU145 prostatic cancer cell lines. We explored the impact of these compounds on programmed cell death, as well as their ability to inhibit cellular invasion. In this study we have demonstrated the safety of these macrocyclic compounds by cytotoxicity tests on ex-vivo human peripheral blood mononuclear cells (PBMCs), and by in vivo subcutaneous administration. Preliminary in vivo tests demonstrated no hepato-, no nephro- and no genotoxicity in Balb/c mice compared to controls treated with cisplatin. These findings suggest these calixpyrroles might be novel therapeutic tools for the treatment of prostate cancer and of particular interest for the treatment of androgen-independent castration-resistant prostate cancer.

Phycocyanin molecules, which are part of light-harvesting complexes in cyanobacteria, can be assembled into mesoscale multilayer nanofilms by the Langmuir-Blodgett technique. Results obtained by quartz crystal microbalance and atomic force microscopy confirm the homogeneity and reproducibility of phycocyanin Langmuir-Blodgett multilayer deposition. We show by cryo-electron microdiffraction that amorphous phycocyanin Langmuir-Blodgett multilayers form, after annealing at 150 °C and cooling to room temperature, a layered nanofibrillar lattice with rotational disorder. Scanning X-ray nanodiffraction suggests that structural transformation is not homogeneous through the film but limited to patches of up to about 10 μm diameter.

Protein X-ray crystallography will remain the most powerful method to obtain the protein 3D atomic structures in foreseeable future. However, the production of the protein crystal as well as it quality (order, intensity of diffraction, radiation stability) remains the major problem. Many important proteins including those of life science interest and pharmaceutical industry impact are difficult to crystallize. The second major problem in protein crystallography is radiation damage of obtaining crystals which can only be partially overcome by existing methods. In the present work we use the protein LB nanotemplate crystallization method – generalized procedure for triggering of crystallization of any given protein, which allows to obtain radiation stable and high quality diffracting crystals for further X-ray analysis by synchrotron radiation. We apply LB nanotemplate method to crystallization of L-asparaginase from Rhodospirillum rubrum. This protein has potential application for combined chemical and enzymatic therapy of malignant blood disorders and therefore for new anticancer drug development. We also compare the diffraction quality of asparagines crystal obtained by classical method and LB nanotemplate and report preliminary X-ray diffraction characterization by synchrotron radiation.

The present report is dedicated to a systematic comparison of crystal structures produced by the nanobiofilm template method and by the classical hanging-drop vapour-diffusion method. Crystals grown by the innovative nanostructured template method appear indeed radiation-resistant even in the presence of a third-generation highly focused beam at the European Synchrotron Radiation Facility. The implications of this finding for protein crystallography are discussed here in terms of water redistribution and of the detailed atomic resolution comparative studies of the two crystal structures with or without nanobiofilm template, as emerging also from circular-dichroism and thermal denaturation studies.

Using Raman spectroscopy and the lysozyme as model system, we investigate the differences in protein conformation before and after Langmuir-Blodgett nanotemplate-induced crystal nucleation and growth. It was found, that the main difference in lysozyme conformation is associated to the higher amount of S-S bonds in lysozyme of LB crystals, probably in C-end of protein, resulting in the higher stiffness of the lysozyme molecules and LB crystal in a whole. Growth in size of LB crystal over time is also accompanied by the formation of S-S bonds. Atomic structure determined by X-ray diffraction correlates to the above pointing to the main differences between LB classical crystals in terms of water molecules environment previously associated to the increased radiation stability of LB crystals.

The crystal growth of biological macromolecules is a very complicated process involving numerous parameters, such as pressure, pH, micro-gravity, photochemical and mechanical induction of nucleation. The utilization of Langmuir–Blodgett (LB) thin film as a template plays an important role in order to produce well-diffracting, stable and radiation-resistant protein crystals. LB nanotemplate crystallization method is a modification of the classical hanging drop vapor diffusion method. We tested four standard proteins, changing different parameters such as protein and salt concentration, number of LB layers etc., in order to verify the real role of LB template. Our results suggest that LB template essentially acts in two way on crystallization: in nucleation and in crystal growth. The possible explanation of these effects is also discussed.

Human lymphocytes gene expression before and after PHA stimulation is monitored by DNASER technology, a novel bioinstrumentation entirely constructed in our laboratories as previously reported. The validity of the DNASER measurements is confirmed by standard fluorescence microscopy equipped with CCD. The human lymphocytes gene expression here experimentally probed using commercially available DNA microarrays such as Human Starter, appears compatible both with independent bioinformatic prediction and with existing experimental data, pointing to MYC as the key gene in the G0–G1 transition induced by PHA in resting lymphocytes. It does not escape our notice that in cell biology and cancer research DNASER technology based on microarray constructed with few leader genes identified from bioinformatics represents a meaningful cost-effective route alternative to massive frequently misleading molecular genomics. J. Cell. Biochem. 97: 1151–1159, 2006. © 2005 Wiley-Liss, Inc.

Protein nanocrystallography, a new technology for crystal growth based on protein nanotemplates, has recently been shown to produce diffracting, stable and radiation-resistant lysozyme crystals. This article, by computing these lysozyme crystals' atomic structures, obtained by the diffraction patterns of microfocused synchrotron radiation, provides a possible mechanism for this increased stability, namely a significant decrease in water content accompanied by a minor but significant alpha-helix increase. These data are shown to be compatible with the circular dichroism and two-dimensional Fourier transform spectra of high-resolution H NMR of proteins dissolved from the same nanotemplate-based crystal versus those from a classical crystal. Finally, evidence for protein direct transfer from the nanotemplate to the drop and the participation of the template proteins in crystal nucleation and growth is provided by high-resolution NMR spectrometry and mass spectrometry. Furthermore, the lysozyme nanotemplate appears stable up to 523 K, as confirmed by a thermal denaturation study using spectropolarimetry. The overall data suggest that heat-proof lysozyme presence in the crystal provides a possible explanation of the crystal's resistance to synchrotron radiation.

Protein nanocrystallography has recently been introduced as a unique nanotechnology-based approach to forming stable protein crystals and to characterize them down to atomic resolution. In particular, a protein nanostuctured template appears to be capable of stimulating nucleation and crystal growth of so far unsolved proteins. In the present communication, aimed at investigating the lysozyme crystal-growth mechanisms with and without nanotemplate, the lysozymes appear to transfer directly from the nanostructured film into the drop to trigger the formation of the crystal, therefore highlighting the physical interpretation of the mechanism for nanotemplate-induced protein crystallization.

Background CD8 cells specific for cytomegalovirus (CMV) provide valuable support in immunocompromised patients. Recent studies have focused on the generation of cytotoxic T lymphocyte (CTL) lines by use of new biotechnological techniques. Yet CD4 cells have been neglected, even though they contribute to the persistence of adoptively transferred CTLs. Methods We identified novel T helper (Th) peptides recognized by CD4 cells on the immunodominant protein pp65. These peptides were used as a mixture to generate CD4 cell lines. Results The peptide library, which, theoretically, is recognized by 85% of white individuals on the basis of the frequency of the relevant human leukocyte antigen class II alleles, was stimulatory for 82% of pp65 responders. T cell lines generated by use of the pool recognized protein antigens. Selection for CMV-specific cells resulted in rapid depletion of allospecific T cells. Selection with individual peptides allowed further selection against potential cross-alloreactivity. Cultured CD4 cells showed no signs of functional senescence. CD4 cells activated by use of a Th peptide helped expand CMV-specific CTLs. Conclusions By use of a simple procedure, an immunodominant peptide library can generate T cell lines from allodonors, for the perspective reconstitution of the Th repertoire in immunocompromised hemopoietic stem-cell transplant recipients.