SELF-IDENTIFICATION IN CROSS-CULTURAL SPACE: WOMEN’S PERSPECTIVE IN MONICA ALI’S BRICK LANE

Abstract. The paper deals with self-identification as one of the most topical problems in view of Britishpostcolonial literature. Women’s multicultural prose, being a bright combination of gender and ethnic discourses, gives an opportunity to form even more interesting ground for discussion. In this regard Brick Lane (2003), the debut novel of half-English half-Bangladeshi Monica Ali is particularly appropriate. Nazneen, a young woman, is in the center of the novel’s narrative. At the age of 18 she and her husband Chanu move from Guripur, a Sylhetian village, to Tower Hamlets, a borough inhabited by the biggest East Pakistani diaspora in London. The novel covers 17 years, from 1985 to 2002. During the period described the main heroine does not only mature, take death of the son, become a mother of2 daughters, but also finds her city and female self. The story presents a peculiar example of cross-cultural and gender issues’ interaction which is reflected through the depiction of the female protagonist in search of identity.Keywords: Monica Ali, Brick Lane, self-identification, multicultural, cross-cultural space, postcolonial novel,female

Dynamics and thermodynamic properties of CXCL7 chemokine

Chemokines form a family of signaling proteins mainly responsible for directing the traffic of leukocytes, where their biological activity can be modulated by their oligomerization state. We characterize the dynamics and thermodynamic stability of monomer and homodimer structures of CXCL7, one of the most abundant platelet chemokines, using experimental methods that include circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy, and computational methods that include the anisotropic network model (ANM), molecular dynamics (MD) simulations and the distance constraint model (DCM). A consistent picture emerges for the effects of dimerization and Cys5-Cys31 and Cys7-Cys47 disulfide bonds formation. The presence of disulfide bonds is not critical for maintaining structural stability in the monomer or dimer, but the monomer is destabilized more than the dimer upon removal of disulfide bonds. Disulfide bonds play a key role in shaping the characteristics of native state dy

The carbohydrate-binding domain on galectin-1 is more extensive for a complex glycan than for simple saccharides: implications for galectin–glycan interactions at the cell surface

gal-1 (galectin-1) mediates cell–cell and cell–extracellular matrix adhesion, essentially by interacting with β-galactoside-containing glycans of cell-surface glycoconjugates. Although most structural studies with gal-1 have investigated its binding to simple carbohydrates, in particular lactose and N-acetyl-lactosamine, this view is limited, because gal-1 functions at the cell surface by interacting with more complex glycans that are heterogeneous in size and composition. In the present study we used NMR spectroscopy to investigate the interaction of human gal-1 with a large (120 kDa) complex glycan, GRG (galactorhamnogalacturonate glycan), that contains non-randomly distributed mostly terminal β(1→4)-linked galactose side chains. We used 15N–1H-HSQC (heteronuclear single quantum coherence) NMR experiments with 15N-enriched gal-1 to identify the GRG-binding region on gal-1 and found that this region covers a large surface area on gal-1 that includes the quintessential lactose-binding site and runs from that site through a broad valley or cleft towards the dimer interface. HSQC and pulsed-field-gradient NMR diffusion experiments also show that gal-1 binds GRG with a gal-1:GRG stoichiometry of about 5:1 (or 6:1) and with average macroscopic and microscopic equilibrium dissociation constants (Kd) of 8×10−6 M and 40×10−6 M (or 48×10−6 M) respectively, indicating stronger binding than to lactose (Kd=520×10−6 M). Although gal-1 may bind GRG in various ways, the glycan can be competed for by lactose, suggesting that there is one major mode of interaction. Furthermore, even though terminal motifs on GRG are Gal-β(1→4)-Gal rather than the traditional Gal-β(1→4)-Glc/GlcNAc (where GlcNAc is N-acetylglucosamine), we show that the disaccharide Gal-β(1→4)-Gal can bind gal-1 at the lactose-binding domain. In addition, gal-1 binding to GRG disrupts inter-glycan interactions and decreases glycan-mediated solution viscosity, a glycan decongestion effect that may help explain why gal-1 promotes membrane fluidity and lateral diffusion of glycoconjugates within cell membranes. Overall, our results provide an insight into the function of galectin in situ and have potential significant biological consequences

Lactose binding to human galectin-7 (p53-induced gene 1) induces long-range effects through the protein resulting in increased dimer stability and evidence for positive cooperativity.

16 pags, 11 figs, 3 tabs. -- Supplementary data for this article are available online at: http://glycob.oxfordjournals.org/lookup/suppl/doi:10.1093/glycob/cwt005/-/DC1The product of p53-induced gene 1 is a member of the galectin family, i.e., galectin-7 (Gal-7). To move beyond structural data by X-ray diffraction, we initiated the study of the lectin by nuclear magnetic resonance (NMR) and circular dichroism spectroscopies, and molecular dynamics (MD) simulations. In concert, our results indicate that lactose binding to human Gal-7 induces long-range effects (minor conformational shifts and changes in structural dynamics) throughout the protein that result in stabilization of the dimer state, with evidence for positive cooperativity. Monte Carlo fits of 15N-Gal-7 HSQC titrations with lactose using a two-site model yield K1 = 0.9 ± 0.6 × 103 M−1 and K2 = 3.4 ± 0.8 × 103 M−1. Ligand binding-induced stabilization of the Gal-7 dimer was supported by several lines of evidence: MD-based calculations of interaction energies between ligand-loaded and ligand-free states, gel filtration data and hetero-FRET spectroscopy that indicate a highly reduced tendency for dimer dissociation in the presence of lactose, CD-based thermal denaturation showing that the transition temperature of the lectin is significantly increased in the presence of lactose, and saturation transfer difference (STD) NMR using a molecular probe of the monomer state whose presence is diminished in the presence of lactose. MD simulations with the half-loaded ligand-bound state also provided insight into how allosteric signaling may occur. Overall, our results reveal long-range effects on Gal-7 structure and dynamics, which factor into entropic contributions to ligand binding and allow further comparisons with other members of the galectin family.This work was supported by a research grant from the National Institutes of Health (CA 096090 to K.H.M.), the RAS program “Molecular and Cellular Biology” RFBR grant (No. 12 04 31360 to E.E.), the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 260600 (“GlycoHIT”), grants CTQ2009-08536 and BFU2009-10052 and a FPI PhD fellowship to M.A.B. from the Spanish Ministry of Science and Innovation and the CIBER of Respiratory Diseases (CIBERES), an initiative from the Spanish Institute of Health Carlos III (ISCIII). E.E. was supported by a Travel Grant from the Minnesota Supercomputing Institute (University of Minnesota) during her stay in the research lab of Prof. K.H. Mayo. I.N. was supported in the Mayo lab by National Institutes of Health Hematology Training Grant (HL 07062

Plant Defensins from a Structural Perspective

Plant defensins form a family of proteins with a broad spectrum of protective activities against fungi, bacteria, and insects. Furthermore, some plant defensins have revealed anticancer activity. In general, plant defensins are non-toxic to plant and mammalian cells, and interest in using them for biotechnological and medicinal purposes is growing. Recent studies provided significant insights into the mechanisms of action of plant defensins. In this review, we focus on structural and dynamics aspects and discuss structure-dynamics-function relations of plant defensins