27 research outputs found
Minority youth, crime, conflict, and belonging in Australia
In recent decades, the size and diversity of the minority population of contemporary western societies has increased significantly. To the critics of immigration, minority youth have been increasingly linked to crime, criminal gangs, anti-social behaviour, and riots. In this article, we draw on fieldwork conducted in Sydney, Australia's largest and most ethnically diverse city, to probe aspects of the criminality, anti-social behaviour, national identity, and belonging of ethnic minority youth in Australia. We conclude that the evidence on minority youth criminality is weak and that the panic about immigrant youth crime and immigrant youth gangs is disproportionate to the reality, drawing on and in turn creating racist stereotypes, particularly with youth of 'Middle Eastern appearance'. A review of the events leading up to the Sydney Cronulla Beach riots of December 2005 suggests that the underlying cause of the riots were many years of international, national, and local anti-Arab, anti-Muslim media discourse, and political opportunism, embedded in changing but persistent racist attitudes and practises. Our argument is that such inter-ethnic conflict between minority and majority youth in Sydney is the exception, not the rule. Finally, we draw on a hitherto unpublished survey of youth in Sydney to explore issues of national identity and belonging among young people of diverse ethnic and religious background. We conclude that minority youth in Sydney do not live 'parallel lives' but contradictory, inter-connected cosmopolitan lives. They are connected to family and local place, have inter-ethnic friendships but are often disconnected to the nation and the flag. © 2009 Springer Science+Business Media B.V
Targeting out of range biomolecules: Chemical labeling strategies for qualitative and quantitative MALDI MS-based detection
Selenazolidine: a selenium containing proline surrogate in peptide science
International audienceIn the search for new peptide ligands containing selenium in their sequences, we investigated L-4-selenazolidine-carboxylic acid (selenazolidine, Sez) as a proline analog with the chalcogen atom in the Îł-position of the ring. In contrast to proteinogenic selenocysteine (Sec) and selenomethionine (SeMet), the incorporation within a peptide sequence of such a non-natural amino acid has never been studied. There is thus a great interest in increasing the possibility of selenium insertion within peptides, especially for sequences that do not possess a sulfur containing amino acid (Cys or Met), by offering other selenated residues suitable for peptide synthesis protocols. Herein, we have evaluated selenazolidine in Boc/Bzl and Fmoc/tBu strategies through the synthesis of a model tripeptide, both in solution and on a solid support. Special attention was paid to the stability of the Sez residue in basic conditions. Thus, generic protocols have been optimized to synthesize Sez-containing peptides, through the use of an Fmoc-Xxx-Sez-OH dipeptide unit. As an example, a new analog of the vasopressin receptor-1A antagonist was prepared, in which Pro was replaced with Sez [3-(4-hydroxyphenyl)-propionyl-D-Tyr(Me)-Phe-Gln-Asn-Arg-Sez-Arg-NH2]. Both proline and such pseudo-proline containing peptides exhibited similar pharmacological properties and endopeptidase stabilities indicating that the presence of the selenium atom has minimal functional effects. Taking into account the straightforward handling of Sez as a dipeptide building block in a conventional Fmoc/tBu SPPS strategy, this result suggested a wide range of potential uses of the Sez amino acid in peptide chemistry, for instance as a viable proline surrogate as well as a selenium probe, complementary to Sec and SeMet, for NMR and mass spectrometry analytical purposes
Oxyfold: A simple and efficient solid-supported reagent for disulfide bond formation
cited By 3International audienceThe synthesis and use of novel polymer-supported reagents for disulfide bond formation is described. This family of supported reagents consists of a series of oxidized methionines grafted onto a solid support. Their cost and the simplicity of their preparation through N-carboxyanhydride polymerization on beads make them reactants of choice for the formation of disulfide bridges in peptides. Copyright © 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Synthesis and conformational analysis of a cyclic peptide obtained via i to i+4 intramolecular side-chain to side-chain azide-alkyne 1,3-dipolar cycloaddition.J Org Chem. Aug 1;.
Intramolecular side-chain to side-chain cyclization is an established approach to achieve stabilization of specific conformations and a recognized strategy to improve resistance toward proteolytic degradation. To this end, cyclizations, which are bioisosteric to the lactam-type side-chain to sidechain modification and do not require orthogonal protection schemes, are of great interest. Herein, we report the employment of Cu(I)-catalyzed 1,3-dipolar cycloaddition of side chains modified with azido and alkynyl functions and explore alternative synthetic routes to efficiently generate 1,4-disubstituted [1,2,3]triazolyl-containing cyclopeptides. The solid-phase assembly of the linear precursor including c-azido norleucine and the propargylglycine (Pra) in positions i and i+4, respectively, was accomplished by either subjecting the resin-bound peptide to selective on-resin diazo transformation of a Lys into the Nle(epsilon-N(3)) or the incorporation of Fmoc-Nle(epsilon-N3)-OH during the stepwise build-up of the resin-bound peptide 1b. Solution-phase Cu(I)-catalyzed 1,3-dipolar cycloaddition converts the linear precursor Ac-Lys-Gly-Nle(epsilon-N(3))-Ser-Ile-Gln-Pra-Leu-Arg-NH(2) (2) into the 1,4-disubstituted [1,2,3]triazolyl-containing cyclopeptide [Ac-Lys-Gly-Xaa(&(1))-Ser-Ile-Gin-Yaa(&(2))-Leu-Arg-NH(2)] [(&(1) (CH(2))(4)-1,4[ 1,2,3]triazolyl-CH(2)&(2))] (3). The conformational preferences of the model cyclopeptide 3 (III), which is derived from the sequence of a highly helical and potent i to i+4 side-chain to side-chain lactam-containing antagonist of parathyroid hormone-related peptide (PTHrP), are compared to the corresponding lactam analogue Ac[Lys(13)(&(1)),Asp(17)(&(2))]hPTHrP(11-19)NH(2) (II). CD and NMR studies of 3 and II in water/hexafluoroacetone (HFA) (50:50, v/v) revealed a high prevalence of turn-helical structures involving in particular the cyclic regions of the molecule. Despite a slight difference of the backbone arrangement, the side-chains of Ser, Gln, and Ile located at the i+1 to i+3 of the ring-forming sequences share the same spatial orientation. Both cyclopeptides differ regarding the location of the turn-helical segment, which in II involves noncyclized residues while in 3 it overlaps with residues involved in the cyclic structure. Therefore, the synthetic accessibility and conformational similarity of i to i+4 side-chain to side-chain cyclopeptide containing the 1,4-disubstituted [1,2,3]triazolyl moiety to the lactam-type one may result in similar bioactivities