Biochemical and functional characterization of Galectin-12, a lectin preferentially expressed in adipocytes

MALLER SEBASTIÁN M.; DI LELLA SANTIAGO; RABINOVICH GABRIEL A; MARIÑO KARINA

Capital Federal

Simposio; GlycoAR; 2014

Fundación Instituto Leloir - Instituto de Biología y Medicina Experimental

Adipose tissue contributes to inflammation-induced obesity by elaborating a variety of factors that stimulate the synthesis of proinflammatory cytokines and chemokines. However, the mechanisms that contribute to create tolerogenic circuits in adipose tissue remain poorly understood. Galectin-12 is a tandem repeat type lectin with preferential expression in lipid droplets of adipocytes. In order to characterize this galectin biochemically and functionally, we designed, implemented and optimized a protocol for recombinant expression of murine Gal-12 into Escherichia coli BL21(DE3) as an expression system. We obtained soluble recombinant His6mGal-12 partially purified by ion exchange chromatography, and its binding to rabbit erythrocytes and three human subtypes (0+,A+,B+) was analyzed by hemagglutination assays. Data obtained by competition assays showed that His6mGal-12 had a preference for sialylated glycans, in accordance with data obtained from glycoarrays and  revealed by molecular modeling approaches, based on the crystallized tandem repeat-type galectins (Gal-4, Gal-8, Gal-9). This biochemical studies were essential as a starting point to study the role of Gal-12 in inflammation-induced obesity and adipogenesis.