Antigenic and immunogenic phage displayed mimotopes as substitute antigens: applications and limitations

The most exciting potential of phage displayed peptide libraries is to obtain small peptide molecules that mimic an antigen, at least with respect to a particular epitope. In addition to their interest as research tools, such mimotopes could in principle be useful as diagnostic tools or for eliciting antibodies to a predefined epitope. However, the reduction of the phage insert sequence to a short peptide that can compete with the antigenic and in particular with the immunogenic properties of the natural antigen faces considerable difficulties. This review assesses critically the antigenicity of phage displayed peptides as free peptides and in different molecular environments. The difficulties to use mimotopes to induce antibodies that bind to the natural antigen (crossreactive immunogenicity) and the considerable discrepancy between antigenicity and immunogenicity of phage-derived peptides are discussed. Peptides selected with antibodies from phage displayed random peptide libraries have raised considerable expectations as low molecular weight substitutes of the natural antigen. This review will focus on the results of phage displayed random peptide libraries screened with antibodies specific for proteins, carbohydrates and nucleic acids and critically examine how the above expectations have been met.     

The influence of contact electrification on the adhesion of dielectric elastic spheres subjected to external loads before detachment

The influence of a static load on the adhesion of an elastic sphere to a rigid smooth surface has been investigated. The change in ratio of the electrostatic component of the adhesion force resulting from the formation of an electric double layer to the molecular one as a result of the contact pressure has been evaluated theoretically. The tearing-off force and the surface density of the charge forming in the contact between the silicone rubber sphere and a steel plate were determined simultaneously. It is shown that the observed increase in sticking force of the sphere after its compression may be explained by an increase in the electrostatic component of the adhesion force, which is proportional to the contact area.     

Synthesis and applications of optically active metallacycles derived from primary amines

The synthesis of optically active cyclopalladated derivatives containing primary amines and their application as resolving agents of Lewis bases is reviewed. Some other applications such as the determination of the absolute configuration of coordinated chiral phosphines and the synthesis of chiral liquid crystals are also presented.     

Phosphoester Hydrolysis: The Incoming Substrate Turns the Bridging Hydroxido Nucleophile into a Terminal One

Identifying the active nucleophile in hydrolysis reactions catalyzed by binuclear hydrolases is a recurrent problem and a matter of intense debate. We report on the phosphate ester hydrolysis by a Fe^IIIFe^II complex of a binucleating ligand. This complex presents activities in the range of those observed for similar biomimetic compounds in the literature. The specific electronic properties of the Fe^IIIFe^II complex allowed us to use ¹H NMR and Mössbauer spectroscopies to investigate the nature of the various species present in the solution in the pH range of 5–10. Both techniques showed that the hydrolysis activity is associated to a μ‐hydroxido Fe^IIIFe^II species. Further ¹H NMR experiments show that binding of anions or the substrate changes this bonding mode suggesting that a terminal hydroxide is the likely nucleophile in these hydrolysis reactions. This view is further supported by the structure determination of the hydrolysis product.     

Mathematical Study of an Inflammatory Model for Atherosclerosis: A Nonlinear Renewal Equation

In this work we study the coupling of a nonlinear renewal equation to an ordinary differential equation. We start with existence and uniqueness issues for the coupled equations and, in particular cases, we study the long-time behaviour. The novelty here is the nonlinearity in the renewal equation. This model arises in the context of atherosclerosis. The renewal part accounts for the inflammatory process: leucocyte recruitment in the arterial wall, differentiation when internalizing low-density lipoprotein (LDL) and death. The ordinary differential equation describes the LDL dynamics in the arterial wall, leucocyte absorption and release in the blood.

     

Thermodynamic modeling of redox equilibria in sodium silicate glasses with low iron content

The available literature data on the content of oxidized and reduced iron forms in molten sodium silicates at temperatures the 1573?C1873 K and partial oxygen pressures 10^?8?0.21 bar have been scrutinized. On the basis of this information, the temperature dependence of the Fe₂O₃ activity coefficient in glass melts containing up to 4 mol % Fe (??Henrian?? solution) has been suggested in the framework of the quasi-chemical model. The results are compared with previous data.