Tandem-repeat lectins: structural and functional insights.

Multivalency in lectins plays a pivotal role in influencing glycan cross-linking, thereby affecting lectin functionality. This multivalency can be achieved through oligomerization, the presence of tandemly repeated carbohydrate recognition domains, or a combination of both. Unlike lectins that rely on multiple factors for the oligomerization of identical monomers, tandem-repeat lectins inherently possess multivalency, independent of this complex process.

Structural and functional analysis of a tandem repeat galacturonic acid-binding lectin from the sea hare Aplysia californica.

A d-galacturonic acid-specific lectin, named AcL, was purified from the sea hare Aplysia californica by galactose-agarose affinity chromatography. AcL has a molecular mass of 27.5 kDa determined by MALDI-TOF mass spectrometry.

Performance of Colombian Silk Fibroin Hydrogels for Hyaline Cartilage Tissue Engineering.

The development and evaluation of scaffolds play a crucial role in the engineering of hyaline cartilage tissue. This work aims to evaluate the performance of silk fibroin hydrogels fabricated from the cocoons of the Colombian hybrid in the in vitro regeneration of hyaline cartilage. The scaffolds were physicochemically characterized, and their performance was evaluated in a cellular model.

Silk fibroin nanocomposites as tissue engineering scaffolds - A systematic review.

Silk fibroin is a protein with intrinsic characteristics that make it a good candidate as a scaffold for tissue engineering. Recent works have enhanced its benefits by adding inorganic phases that interact with silk fibroin in different ways. A systematic review was performed in four databases to study the physicochemical and biological performance of silk fibroin nanocomposites.

Organization of the extracellular portion of the macrophage galactose receptor: a trimeric cluster of simple binding sites for N-acetylgalactosamine.

The properties of the human macrophage galactose receptor have been investigated. Specificity for N-acetylgalactosamine (GalNAc) residues with exposed 3- and 4-hydroxyl groups explains virtually all of the results obtained from a recently expanded array of synthetic glycans and is consistent with a model for the structure of the binding site. This simple interaction is sufficient to explain the ability of the receptor to bind to tumor-cell glycans bearing Tn and sialyl-Tn antigens, but not to more elaborate O-linked glycans that predominate on normal cells.

Engineered carbohydrate-recognition domains for glycoproteomic analysis of cell surface glycosylation and ligands for glycan-binding receptors.

Modular calcium-dependent carbohydrate-recognition domains (CRDs) of mammalian glycan-binding receptors (C-type lectins), engineered to have novel glycan-binding selectivity, have been developed as tools for the study of glycans on cell surfaces. Structure-based specificity swapping between domains can be complemented by empirical characterization of ligand-binding specificity using glycan arrays. Both natural and modified CRDs can be used as probes for detecting and isolating glycoproteins that bear specific glycan epitopes and that act as target ligands for glycan-binding receptors.

Identification of novel contributions to high-affinity glycoprotein-receptor interactions using engineered ligands.

Engineered receptor fragments and glycoprotein ligands employed in different assay formats have been used to dissect the basis for the dramatic enhancement of binding of two model membrane receptors, dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and the macrophage galactose lectin, to glycoprotein ligands compared to simple sugars. These approaches make it possible to quantify the importance of two major factors that combine to enhance the affinity of single carbohydrate-recognition domains (CRDs) for glycoprotein ligands by 100-to 300-fold. First, the presence of extended binding sites within a single CRD can enhance interaction with branched glycans, resulting in increases of fivefold to 20-fold in affinity.