Biorecognition of Chemically Modified Bovine Serum Albumin with Lactose Prepared under Different Conditions

Abstract

Glycoconjugates consist of glycans attached to proteins or lipids. Glycans are involved in important biological functions such as trafficking of glycoconjugates, mediation, and modulation of cell adhesion and signaling. This study was conducted to obtain neoglycoconjugates containing a large number of carbohydrates, added through the condensation of reducing sugars with protein amino groups, whose structures were recognized by lectins. Neoglycoconjugates (BSA-Lac) of bovine serum albumin (BSA) with d-lactose were obtained using two sets of glycation conditions, each previously selected by its ability to glycate proteins extensively. The conditions included dry heat at 60 degrees C (for 7, 14, 21, and 28 days) and wet heat in 43% relative humidity (RH) at 50 degrees C (for 5, 10, 15, and 20 h). Products were characterized by gel electrophoresis, tryptophan fluorescence emission spectra, mass spectrometry, free amino group analysis, and their biological recognition established by a galactose-specific lectin and Escherichia coli K88 adhesins. BSA-Lac when compared to BSA revealed an increase in monomer mass due to addition of either 13 (dry heat) or 14 (wet heat) lactoses and formation of polymers (in wet conditions). All BSA-Lac products showed reduced intensity of intrinsic fluorescence, decreased amino groups' availability, and were recognized by Ricinus communis I lectin (RCAI) and by E. coli K88 adhesins. Overall, glycation using both conditions was time-dependent, but greater biorecognition was observed with wet-heat products, due to a higher global glycation and/or to the carbohydrate accessibility. The strategy used in this work represents a simple procedure to obtain glycoconjugates that could be used for recognition studies in biological systems.

Conjugates of Bovine Serum Albumin with Chitin Oligosaccharides Prepared through the Maillard Reaction

“…Recently, proteins such as serum albumin (porcine and bovine) chemically modified with disaccharides were biorecognized by plant lectins and bacterial adhesins − . Furthermore, porcine serum albumin conjugated with lactose could compete in vitro with intestinal bacterial natural ligands .…”

K88 Fimbrial Adhesin Targeting of Microspheres Containing Gentamicin Made with Albumin Glycated with Lactose

“…K88 strains of ETEC that cause diarrhea in pigs possess an adhesin essential for disease to occur [ 19 ]. Recent reports show that K88 adhesin targets specific receptors containing galactose exposed when using lactosylated albumin [ 13 , 14 ]. In this study, the formulation of stabilized microspheres, antibiotic carriers, using lactosylated albumin as encapsulation polymer, was examined.…”

“…Our group has reported that BSA chemically modified with lactose (BSA-Lac) leads to recognition of piglet pathogens, such as enterotoxigenic Escherichia coli K88, and by carbohydrate-binding proteins from Ricinus communis agglutinin I (RCA I), a galactose specific lectin [ 13 , 14 ]. The aim of this work was to use BSA-Lac as a polymer to obtain lactosylated microspheres (MS-Lac) that carry gentamicin and to stabilize them by crosslinking.…”

Molecular recognition of glyconanoparticles by RCA and E. coli K88 - designing transports for targeted therapy

“…This coupling reaction of protein with sugar produces neoglycans. Previous reports indicate that glycation is favored by temperatures above 60°C, alkaline pH, and influenced by moisture and reaction time (Ledesma-Osuna et al, 2009;Sarabia-Sainz et al, 2011). Other factors, such as water activity, intrinsic properties of protein and sugar, and the amino group-reducing sugar ratio, influence the yields and types of the Maillard reaction products.…”