Estimate and mapping of the activity of airborne pollen sources

Summary This contribution presents a procedure for estimating the distribution of pollen sources and mapping their activity. Particular reference is made to the example of mapping the pollen emissions ofCastanea sativa, in the Reno valley near Bologna (Italy), achieved with numerical techniques and starting from basic maps (vegetation, topographic and pedologic), phenological observations and pollen production data.     

Cyclization under mild conditions of anthraniloyl- and N-methyl-anthraniloyl dipeptides

Anthraniloyl- and N-methyl-anthraniloyl dipeptides containing C-terminal L and D proline residues have been synthesized and subjected to cyclization reaction under mild conditions. The influence of substituents and of the chirality of the residues on the output of the reaction is discussed.     

Synthetic amatoxin analogues. II. A proton n.m.r. study of S-deoxo-Ile3-(L)Ala5 and S-deoxo-Ile3-(D)Ala5-amaninamide

Amatoxin analogues with D and L-Ala substitutions in position 5 have been studied by means of 1- and 2-dimensional n.m.r. spectroscopy at 500 MHz. The assignment of all resonances for both analogues has been carried out mostly with the use of COSY and NOESY type experiments. Temperature coefficients for the amide NH protons have been measured and the data compared to known amatoxin structures. The results obtained demonstrate that the rigidity of the bicyclic amatoxin framework is preserved in the D and L-Ala5 analogues, although the temperature coefficients point to intramolecular hydrogen bonds stronger in the case of the L-Ala analogue. The 10-fold decrease of biological activity is discussed in terms of structural features involving also the Trp4 indole accessibility.     

Printed in the Holiday Mood

Teachers' careers are often considered to consist of two parts: pre-service and in-service. In-service refers to the entire time between a teacher's entry and exit from the profession. Recent research suggests teachers' careers actually consistent of several parts, known as phases or stages and, collectively, as the career cycle. This further suggests that as they pass through different stages, teachers' professional development needs may change. This article presents a review of literature on the career cycle, examines the portion known as the “second stage,” and discusses the policy and professional development implications for music teachers.     

Distant Homology Modeling of LCAT and Its Validation through In Silico Targeting and In Vitro and In Vivo Assays

LCAT (lecithin:cholesterol acyltransferase) catalyzes the transacylation of a fatty acid of lecithin to cholesterol, generating a cholesteryl ester and lysolecithin. The knowledge of LCAT atomic structure and the identification of the amino acids relevant in controlling its structure and function are expected to be very helpful to understand the enzyme catalytic mechanism, as involved in HDL cholesterol metabolism. However - after an early report in the late ‘90 s - no recent advance has been made about LCAT three-dimensional structure. In this paper, we propose an LCAT atomistic model, built following the most up-to-date molecular modeling approaches, and exploiting newly solved crystallographic structures. LCAT shows the typical folding of the α/β hydrolase superfamily, and its topology is characterized by a combination of α-helices covering a central 7-strand β-sheet. LCAT presents a Ser/Asp/His catalytic triad with a peculiar geometry, which is shared with such other enzyme classes as lipases, proteases and esterases. Our proposed model was validated through different approaches. We evaluated the impact on LCAT structure of some point mutations close to the enzyme active site (Lys218Asn, Thr274Ala, Thr274Ile) and explained, at a molecular level, their phenotypic effects. Furthermore, we devised some LCAT modulators either designed through a de novo strategy or identified through a virtual high-throughput screening pipeline. The tested compounds were proven to be potent inhibitors of the enzyme activity.