Transglutaminase-mediated modification of ovomucoid: effects on its trypsin inhibitory activity and antigenic properties

Hen egg can cause food hypersensitivity in infants and young children, and ovomucoid is the most allergenic factor among proteins contained in egg white. Since proteinase treatment, a well-recognized strategy in reducing food allergenicity, is ineffective when applied to ovomucoid because of its ability to act as trypsin inhibitor, we investigated the possibility of reducing the ovomucoid antiprotease activity and antigenic properties by covalently modifying its structure. The present paper reports data showing the ability of the Gln115 residue of ovomucoid to act as an acyl donor substrate for the enzyme transglutaminase and, as a consequence, to give rise to a covalent monodansylcadaverine conjugate of the protein in the presence of both enzyme and the diamine dansylated derivative. Moreover, we demonstrated that the obtained structural modification of ovomucoid significantly reduced the capability of the protein to inhibit trypsin activity, also having impact on its anti-ovomucoid serum-binding properties.     

Synthesis of Isoxazolidino Analogues of 2′,3′-Dideoxynucleosides

Abstract

The complete set of the 4′-aza analogues of 2′,3′-dideoxynucleosides was synthesized by cycloaddition of N-tetrahydropiranyl or N-trityl methylene nitrones on suitably protected vinyl nucleobases. The convertible nucleoside approach was used in the preparation of cytosine and 5-methyl cytosine analogues.     

Identification of Prunus armeniaca cultivars by RAPD and SCAR markers

Nineteen cultivars of apricot (Prunus armeniaca) were distinguished using random amplified polymorphic DNA (RAPD) markers. One decamer out of 44 used was useful to differentiate cultivars of the Campania Region from those of Northern Italy, North America and Greece. A sequence characterized amplified region (SCAR) marker was obtained. The results provide a protocol to fingerprint DNA of apricots as an efficient way to quality control and fraud prevention.     

Co-fibrillogenesis of Wild-type and D76N β2-Microglobulin: THE CRUCIAL ROLE OF FIBRILLAR SEEDS*

The amyloidogenic variant of β₂-microglobulin, D76N, can readily convert into genuine fibrils under physiological conditions and primes in vitro the fibrillogenesis of the wild-type β₂-microglobulin. By Fourier transformed infrared spectroscopy, we have demonstrated that the amyloid transformation of wild-type β₂-microglobulin can be induced by the variant only after its complete fibrillar conversion. Our current findings are consistent with preliminary data in which we have shown a seeding effect of fibrils formed from D76N or the natural truncated form of β₂-microglobulin lacking the first six N-terminal residues. Interestingly, the hybrid wild-type/variant fibrillar material acquired a thermodynamic stability similar to that of homogenous D76N β₂-microglobulin fibrils and significantly higher than the wild-type homogeneous fibrils prepared at neutral pH in the presence of 20% trifluoroethanol. These results suggest that the surface of D76N β₂-microglobulin fibrils can favor the transition of the wild-type protein into an amyloid conformation leading to a rapid integration into fibrils. The chaperone crystallin, which is a mild modulator of the lag phase of the variant fibrillogenesis, potently inhibits fibril elongation of the wild-type even once it is absorbed on D76N β₂-microglobulin fibrils.     

SpeedHap: an accurate heuristic for the single individual SNP haplotyping problem with many gaps, high reading error rate and low coverage

Single nucleotide polymorphism (SNP) is the most frequent form of DNA variation. The set of SNP's present in a chromosome (called the em haplotype) is of interest in a wide area of applications in molecular biology and biomedicine, including diagnostic and medical therapy. In this paper we propose a new heuristic method for the problem of haplotype reconstruction for (portions of) a pair of homologous human chromosomes from a single individual (SIH). The problem is well known in literature and exact algorithms have been proposed for the case when no (or few) gaps are allowed in the input fragments. These algorithms, though exact and of polynomial complexity, are slow in practice. When gaps are considered no exact method of polynomial complexity is known. The problem is also hard to approximate with guarantees. Therefore fast heuristics have been proposed. In this paper we describe SpeedHap, a new heuristic method that is able to tackle the case of many gapped fragments and retains its effectiveness even when the input fragments have high rate of reading errors (up to 20%) and low coverage (as low as 3). We test SpeedHap on real data from the HapMap Project.     

Transglutaminases expression in human supraspinatus tendon ruptures and in mouse tendons

The ethiopathogenesis of rotator cuff disease remains poorly understood. Many studies advocate the importance of extra cellular matrix for the homeostasis of connective tissue. Transglutaminase enzymes family has been studied in the context of connective tissue formation and stabilisation. Here, we investigated transglutaminases expression pattern in biopsies of normal and injured supraspinatus tendons of human shoulders and in the Achilles tendons of transglutaminase 2 knock-out and wild-type mice. Our results show that different transglutaminase family members are differentially expressed in human and mouse tendons, and that transglutaminase 2 is down-regulated at mRNA and protein levels upon human supraspinatus tendon ruptures.