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December Galectin-3 (Gal-3) is secreted by activated macrophages. In hypertension, Gal-3 is a marker for hypertrophic hearts prone to develop heart failure. Gal-3 infused in pericardial sac leads to cardiac inflammation, remodeling, and dysfunction. N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP), a naturally occurring tetrapeptide, prevents and reverses inflammation and collagen deposition in the heart in hypertension and heart failure postmyocardial infarction. In the present study, we hypothesize that Ac-SDKP prevents Gal-3-induced cardiac inflammation, remodeling, and dysfunction, and these effects are mediated by the transforming growth factor (TGF)-[beta]/Smad3 signaling pathway. Adult male rats were divided into four groups and received the following intrapericardial infusion for 4 wk: 1) vehicle (saline, n = 8); 2) Ac-SDKP (800 [micro]g x [kg.sup.-1] x [day.sup.-1], n = 8); 3) Gal-3 (12 [micro]g/day, n = 7); and 4) Ac-SDKP + Gal-3 (n = 7). Left ventricular ejection fraction, cardiac output, and transmittal velocity were measured by echocardiography; inflammatory cell infiltration, cardiomyocyte hypertrophy, and collagen deposition in the heart by histological and immunohistochemical staining; and TGF-[beta] expression and Smad3 phosphorylation by Western blot. We found that, in the left ventricle, Gal-3 1) enhanced macrophage and mast cell infiltration, increased cardiac interstitial and perivascular fibrosis, and causes cardiac hypertrophy; 2) increased TGF-[beta] expression and Smad3 phosphorylation; and 3) decreased negative change in pressure over time response to isoproterenol challenge, ratio of early left ventricular filling phase to atrial contraction phase, and left ventricular ejection fraction. Ac-SDKP partially or completely prevented these effects. We conclude that Ac-SDKP prevents Gal-3-induced cardiac inflammation, fibrosis, hypertrophy, and dysfunction, possibly via inhibition of the TGF-[betya]/Smad3 signaling pathway. N-acetyl-seryl-aspartyl-lysyl-proline; cardiac dysfunction; fibrosis; inflammation

Photoderivatized polymer-coated gold surfaces have been developed following a perfluorophenylazide-based double ligation strategy. Gold-plated quartz crystal microbalance (QCM) crystals were initially covalently functionalized with a monolayer of poly(ethylene glycol) (PEG), using photoor thermolytic nitrene formation and insertion. The polymer surfaces were subsequently used as substrates for photoinsertion of carbohydrate-derivatized photoprobes, yielding different recognition motifs for selective protein binding. The resulting robust and biocompatible sensor surfaces were applied to a flow-through QCM instrument for monitoring lecfin-carbohydrate interactions in real time. The results clearly show the predicted lectin selectivity, demonstrating the applicability of the approach.

Chemoenzymatic synthesis of the respective galactosylated and alpha2,3/6-sialylated N-glycans is performed to address the issue whether core fucosylation and the bisecting N-acetylglucosamine residue modulate ligand properties of complex-type biantennary N-glycans. The study results help in devising new, non-natural modifications to realize the full potential of glycoengineering for diagnostic and therapeutic purposes.

Binding of a series of sialylated and non-sialylated cell surface carbohydrates to bovine heart galectin-1, recombinant murine galectin-3, and recombinant human galectin-7 was investigated by isothermal titration microcalorimetry (ITC) and hemagglutination inhibition measurements. Galectin-7 shows nearly equal affinities for lactose and Gall[beta] (1-4)GlcNAc (LacNAc-II). Galectin-7, however, displays six- and 11-fold weaker affinity for LacNAc-II compared with galectins-1 and -3, respectively. The affinity of galectin-7 for LacNAc-II containing oligosaccharides is also weaker than the other two galectins. ITC measurements show that all three galectins bind to di- and trimeric oligomers of LacNAc-II, which are epitopes found in poly-N-acetyllactosamine chains of glycoprotein receptors, with affinity constants similar to that of LacNAc-II. The binding valencies of the di- and trimeric LacNAc-II oligomers were observed to be one from ITC measurements, indicating formation of 1:1 complexes with all three galectins. Thus, galectins-1, -3, and -7 all possess binding sites that primarily accommodate one LacNAc-II moiety per monomer of protein. Sialylated oligosaccharides show different specificities for the three galectins. While 2,3-sialyl LacNAc-II binds to all three galectins, 2,6-sialyl LacNAc-II fails to bind to any of the galectins; 2,6-sialylated diLacNAc binds well to galectin-3 and galectin-7, but only weakly to galectin-1. Similar results are obtained with 2,6-sialyl lacto-N-neo-tetraose, which has a reducing end lactose moiety. Thus, unlike galectin-l, which predominantly recognizes non-reducing terminal LacNAc-II residues in oligosaccharides, galectins-3 and -7 recognize both non-reducing terminal LacNAc-II residues as well as internal LacNAc-II and lactose residues in sialylated and non-sialylated oligosaccharides. Key words: isothermal titration microcalorimetry, galectins, binding specificities, lectins, carbohydrates.

Research has been conducted on the carbohydrate-binding peptides. The reactivity of these peptides has been investigated and the results are presented.

The article explains the processes and the mechanisms that are involved in the synthesis of various bivalent lactosides based on several different scaffolds. The results prove that the compounds with more flexibility lead to better protection of the human cells against the plant toxin binding.

The cloning of full-length cDNA for the first avian tandem-repeat-type galectin which is termed chicken galectin (CG-8) based on its sequence similarity to galectin-8 from mammals is reported. Two proteins with linkers of either 9 (CG-8I) or 28 amino acids (CG-8II) generated by alternative splicing formed monomers with a shape comparable to that of the proto-type proteins CG-1A/B in solution, act as cross-linkers in hemagglutination, and bind cells with a strict dependence on galactose.

Negative cooperativity in the isothermal titration microcalorimetry (ITC) binding data of asialofeutin (ASF), a glycoprotein that possesses nine LacNAc epitopes, to galectin-1, -2, -3, -4, -5, and -7 and truncated, monomer version of galectin-3 and -5 which are members of a family of animal lectins is demonstrated. The results indicate that the galactins bind with fractional, high affinities to multivalent glycoproteins such as ASF, independent of the quaternary structures of the galectins.