Bauhinia monandra leaf lectin (BmoLL) conjugated with quantum dots as fluorescent nanoprobes for biological studies: application to red blood cells

Abstract

Carbohydrates perform important physiological functions in eukaryotic and prokaryotic cells. Indeed, alterations in glycan patterns may be associated with disorders. The analysis of these sugars can be reached using nanoprobes composed by lectins associated with fluorescent nanoparticles. This study reports the conjugation of a galactose-binding lectin (BmoLL) isolated from Bauhinia monandra leaves with quantum dots (QDs) by adsorption. QDs-BmoLL conjugates showed bright fluorescence and the hemagglutination assay revealed that the lectin preserved its carbohydrate-binding ability after the conjugation. To evaluate the efficiency/specificity of the bioconjugate, ABO human red blood cells (RBCs) were used as biological models and the labeling was analyzed by flow cytometry. Among ABO blood groups, higher labeling (71.7 ± 5.9%) was detected for B-type RBCs, whose antigens have galactose in their structure. The specificity of labeling was confirmed since A- and O-types RBCs incubated with QDs-BmoLL, as well as B-type cells incubated with previously galactose-inhibited conjugates, were labeled below 6%. In AB-type RBCs, which simultaneously have B and A (N-acetylgalactosamine) antigens on their membrane, the labeling was ca. 14.1 ± 4.8%. Therefore, a successful conjugation was reached and QDs-BmoLL conjugates can be considered promising fluorescent nanoprobes for biological investigations.

Effect of Bauhinia monandra Kurz Leaf Preparations on Embryonic Stages and Adult Snails of Biomphalaria glabrata (Say, 1818), Schistosoma mansoni Cercariae and Toxicity in Artemia salina

“…The rutin content for the saline extract and fraction was 0.53 ± 0.0010% and 0.24 ± 0.0033%, respectively. Our results are similar to studies with BmoLL conjugated with quantum dots [ 20 ] which showed an HA of 1024 in hemagglutination tests, as well as in studies with extract of Viola tricolor [ 27 ] and ethanol extract of Caesalpinia pyramidalis [ 28 ] regarding the presence of this metabolites.…”

“…In this context, plants of the genus Bauhinia (Fabaceae family) are widely found on continents where endemic diseases for schistosomes are reported, such as Africa and Asia, as well as Central and South America [ 17 ]. In Brazil, Bauhinia monandra Kurz [ 18 ] is popularly known as “pata-de-vaca” and several of its biotechnological applications have already been reported [ 19 , 20 ]. For example, lectin, a protein that binds to galactose carbohydrate by specific and reversible recognition, was purified to homogeneity from the leaves of B. monandra (BmoLL, B. monandra leaf lectin) and presented insecticide activity against Anagasta kuehniella (Lepidoptera: Pyralidae), Zabrotes subfasciatus and Callosobruchus maculatus (Coleoptera: Bruchidae) [ 21 , 22 ].…”

Mannose-binding lectin conjugated to quantum dots as fluorescent nanotools for carbohydrate tracing

“…Although the conjugate had a decrease in the fluorescence intensity, it continued highly fluorescent, as shown in the inset of figure 4(B). This optical behavior was similar to the conjugates prepared from MSA-CdTe QDs and Con A, Cramoll, or BmoLL lectins, using the adsorption strategy [23,54,55].…”

Aeromonas and Human Health Disorders: Clinical Approaches

“…Aeromonas can grow on selective and differential enteric agars; however, the carbohydrate contained in these agars can influence the growth of these microorganisms and is therefore not ideal for primary isolation in fecal samples of Aeromonas . For example, the ability to ferment carbohydrates can depend on the species, carbohydrates, such as xylose and lactose, can inhibit the growth of some Aeromonas , and a false-negative oxidase reaction can occur due to an acidification process in the medium ( Oliveira et al, 2020 ).…”