Search results for "Serp"
showing 10 items of 205 documents
On the molecular structure of human neuroserpin polymers
2012
The polymerization of serpins is at the root of a large class of diseases; the molecular structure of serpin polymers has been recently debated. In this work, we study the polymerization kinetics of human neuroserpin by Fourier Transform Infra Red spectroscopy and by time-lapse Size Exclusion Chromatography. First, we show that two distinct neuroserpin polymers, formed at 45 and 85°C, display the same isosbestic points in the Amide I' band, and therefore share common secondary structure features. We also find a concentration independent polymerization rate at 45°C suggesting that the polymerization rate-limiting step is the formation of an activated monomeric species. The polymer structures…
Ligand structures of synthetic deoxa-pyranosylamines with raucaffricine and strictosidine glucosidases provide structural insights into their binding…
2014
Insight into the structure and inhibition mechanism of O-β-d-glucosidases by deoxa-pyranosylamine type inhibitors is provided by X-ray analysis of complexes between raucaffricine and strictosidine glucosidases and N-(cyclohexylmethyl)-, N-(cyclohexyl)- and N-(bromobenzyl)-β-d-gluco-1,5-deoxa-pyranosylamine. All inhibitors anchored exclusively in the catalytic active site by competition with appropriate enzyme substrates. Thus facilitated prospective elucidation of the binding networks with residues located at <3.9 A distance will enable the development of potent inhibitors suitable for the production of valuable alkaloid glucosides, raucaffricine and strictosidine, by means of synthesis in …
The Structure of Rauvolfia serpentina Strictosidine Synthase Is a Novel Six-Bladed β-Propeller Fold in Plant Proteins
2006
Abstract The enzyme strictosidine synthase (STR1) from the Indian medicinal plant Rauvolfia serpentina is of primary importance for the biosynthetic pathway of the indole alkaloid ajmaline. Moreover, STR1 initiates all biosynthetic pathways leading to the entire monoterpenoid indole alkaloid family representing an enormous structural variety of ∼2000 compounds in higher plants. The crystal structures of STR1 in complex with its natural substrates tryptamine and secologanin provide structural understanding of the observed substrate preference and identify residues lining the active site surface that contact the substrates. STR1 catalyzes a Pictet-Spengler–type reaction and represents a novel…
New Alkaloids of the Sarpagine Group from Rauvolfia serpentina Hairy Root Culture
2002
Three new monoterpenoid indole alkaloids, 19(S),20(R)-dihydroperaksine (1), 19(S),20(R)-dihydroperaksine-17-al (2), and 10-hydroxy-19(S),20(R)-dihydroperaksine (3), along with 16 known alkaloids 4-19 were isolated from hairy root culture of Rauvolfia serpentina, and their structures were elucidated by 1D and 2D NMR analyses. Taking into account the stereochemistry of the new alkaloids and results of preliminary enzymatical studies, the putative biosynthetical relationships between the novel alkaloids are discussed.
Giacomo Serpotta. Allegoria della Fede e della Clemenza
2015
Analisi storico critica dei frammenti in stucco di Giacomo Serpotta provenienti dalla chiesa di San Matteo e custoditi al Museo Diocesano di Palermo. Descrizione, analisi e contestualizzazione nella temperie culturale di riferimento.
El yacimiento prehistórico de Regadiuet (Alcoi, Alacant): Datos preliminares de la secuencia mesolítica y neolítica.
2008
Presentamos en este texto un avance de resultados de la primera campaña efectuada en el yacimiento prehistórico al aire libre de Regadiuet (Alcoi, Alacant). Los materiales de prospección previamente analizados parecían augurar una dilatada secuencia que, al menos desde el mesolítico geométrico, aportaba también evidencias de ocupaciones posteriores, ya del Neolítico antiguo. Los trabajos de campo han confirmado buena parte de es tas suposiciones al localizar una serie de estructuras excavadas atribuidas al Neolítico antiguo de la secuencia regional. Queda corroborada igualmente la existencia de niveles precerámicos, aspecto que confirma la recurrencia en la apropiación de este espacio por…
L’Oratorio del Rosario in San Domenico
2002
Si tratta della prima monografia sul famoso oratorio stuccato da Giacomo Serpotta nel secondo decennio del XVII secolo. Il volume ricostruisce le vicende relative alla fondazione a partire dalla compagnia committente dei lavori nel 1568. Si individuano i lacerti di stucco dovuti all'intervento precedente di Pietro Novelli e i passaggi che portano al Serpotta, di cui è descritto l'intero apparato dal punto di vista iconografico e con una nuova lettura iconologica. Non viene tralasciata l'importante quadreria con Van Dyck, Giovan Andrea De Ferrari, Borremans, frutto di una vena collezionistica, di cui si offrono nuove attribuzioni e spunti per successivi approfondimenti, anche tramite fonti i…
Multiperiodic pulsations in the Be stars NW Serpentis and V1446 Aquilae
2007
Aims.We present accurate photometric time series of two Be stars: NW Ser and V1446 Aql . Both stars were observed at the Observatorio de Sierra Nevada (Granada) in July 2003 with an automatic four-channel Strömgren photometer. We also present a preliminary theoretical study showing that the periodic variations exhibited by these stars can be due to pulsation. Methods.An exhaustive Fourier analysis together with a least-square fitting has been carried out on the time series for all four Strömgren bands. Several independent frequencies and non-periodic trends explain most of the variance. A theoretical non-adiabatic code applied to stellar models for these stars shows that g-modes are unstabl…
GETTING A MULTIMEDIA MESSAGE ACROSS IN PALERMO INFORMATION TECHNOLOGY AND ARTISTIC HERITAGE IN AN AREA WITH A LOW RATE OF DEVELOPMENT
2000
It is not that our cultural heritage should be regarded as riches that may be turned to profit; it is that the decay into which many monuments and historic sites have fallen by making them part of society's wealth-generating structures would represent an opportunity for otherwise run-down areas to get back on their feet again. For that to happen, communication will be an indispensable tool, making our cultural wealth easily accessible to all and allowing it to be taken advantage of. Palermo has this problem. It has a marvellous cultural heritage but no global plan for keeping the outside world informed and bringing itself to the attention of potential visitors.