Selection of thrombin-binding aptamers by using computational approach for aptasensor application.

The possibility of introducing a computationally assisted method to study aptamer-protein interaction was evaluated with the aim of streamlining the screening and selection of new aptamers. Starting from information on the 15-mer (5'-GGTTGGTGTGGTTGG-3') thrombin binding aptamer (TBA), a library of mutated DNA sequences (994 elements) was generated and screened using shapegauss a shape-based scoring function from openeye software to generate computationally derived binding scores. The TBA and three other mutated oligonucleotides, selected on the basis of their binding score (best, medium, worst), were incorporated into surface plasmon resonance (SPR) biosensors.

Piezoelectric biosensors for aptamer-protein interaction.

Aptamers can be considered as a valid alternative to antibodies or other biomimetic receptors for the development of biosensors and other analytical methods. The production of aptamers is commonly performed by the SELEX (Systematic Evolution of Ligands by Exponential Enrichment) process, which, starting from large libraries of oligonucleotides, allows the isolation of large amounts of functional nucleic acids by an iterative process of in vitro selection and subsequent amplification through polymerase chain reaction. Aptamers are suitable for applications based on molecular recognition as analytical, diagnostic, and therapeutic tools.

Analytical performances of aptamer-based sensing for thrombin detection.

Aptamer-based assays represent a modern and attractive approach in bioanalytical chemistry. The DNA thrombin aptamer has been extensively investigated, and the coupling of this aptamer to different transduction principles has demonstrated the wide applicability of aptamers as bioreceptors in bioanalytical assays. The goal of this work was to critically evaluate all the parameters that can influence the sensor performances by using the thrombin aptamer immobilized onto piezoelectric quartz crystals.

Expression of gC1q-R/p33 and its major ligands in human atherosclerotic lesions.

A growing body of evidence supports the hypothesis that atherosclerosis has an inflammatory component, and that immune mechanisms, including complement activation, are likely to be involved. gC1q-R/p33 (gC1q-R) is a multifunctional and multicompartmental cellular protein, which is postulated to play a role in inflammation and thrombosis by interacting with C1q and high molecular weight kininogen (HK). To examine the expression of gC1q-R and its major ligands, C1q and HK, in human atherosclerotic lesions, sections of carotid arteries removed during endarterectomy and coronary arteries obtained at autopsy were stained with specific polyclonal or monoclonal antibodies.

Platelets, circulating tissue factor, and fibrin colocalize in ex vivo thrombi: real-time fluorescence images of thrombus formation and propagation under defined flow conditions.

Although it is generally accepted that the initial event in coagulation and intravascular thrombus formation is the exposure of tissue factor (TF) to blood, there is still little agreement about the mechanisms of thrombus propagation and the identities of the molecular species participating in this process. In this study, we characterized the thrombotic process in real-time and under defined flow conditions to determine the relative contribution and spatial distribution of 3 components of the thrombi: circulating or blood-borne TF (cTF), fibrin, and platelets. For this purpose, we used high-sensitivity, multicolor immunofluorescence microscopy coupled with a laminar flow chamber.