Analyses of Aloe Polysaccharides Using Carbohydrate Microarray Profiling.

Background: As the popularity of Aloe vera extracts continues to rise, a desire to fully understand the individual polymer components of the leaf mesophyll, their relation to one another, and the effects they have on the human body are increasing. Polysaccharides present in the leaf mesophyll have been identified as the components responsible for the biological activities of A. vera, and they have been widely studied in the past decades. However, the commonly used methods do not provide the desired platform to conduct large comparative studies of polysaccharide compositions, as most of them require a complete or near-complete fractionation of the polymers. Objective: The objective for this study was to assess whether carbohydrate microarrays could be used for the high-throughput analysis of cell wall polysaccharides in aloe leaf mesophyll. Methods: The method we chose is known as comprehensive microarray polymer profiling (CoMPP) and combines the high-throughput capacity of microarray technology with the specificity of molecular probes. Results: Preliminary findings showed that CoMPP can successfully be used for high-throughput screening of aloe leaf mesophyll tissue. Seventeen species of Aloe and closely related genera were analyzed, and a clear difference in the polysaccharide compositions of the mesophyll tissues was seen. Conclusions: These preliminary data suggest that the polysaccharides vary between species and that true species of Aloe may differ from segregate genera.

A multivariate approach for high throughput pectin profiling by combining glycan microarrays with monoclonal antibodies.

Pectin-one of the most complex biomacromolecules in nature has been extensively studied using various techniques. This has been done so in an attempt to understand the chemical composition and conformation of pectin, whilst discovering and optimising new industrial applications of the polymer. For the last decade the emergence of glycan microarray technology has led to a growing capacity of acquiring simultaneous measurements related to various carbohydrate characteristics while generating large collections of data. Here we used a multivariate analysis approach in order to analyse a set of 359 pectin samples probed with 14 different monoclonal antibodies (mAbs). Principal component analysis (PCA) and partial least squares (PLS) regression were utilised to obtain the most optimal qualitative and quantitative information from the spotted microarrays. The potential use of microarray technology combined with chemometrics for the accurate determination of degree of methyl-esterification (DM) and degree of blockiness (DB) was assessed.

Carbohydrate microarrays in plant science.

Almost all plant cells are surrounded by glycan-rich cell walls, which form much of the plant body and collectively are the largest source of biomass on earth. Plants use polysaccharides for support, defense, signaling, cell adhesion, and as energy storage, and many plant glycans are also important industrially and nutritionally. Understanding the biological roles of plant glycans and the effective exploitation of their useful properties requires a detailed understanding of their structures, occurrence, and molecular interactions. Microarray technology has revolutionized the massively high-throughput analysis of nucleotides, proteins, and increasingly carbohydrates. Using microarrays, the abundance of and interactions between hundreds and thousands of molecules can be assessed simultaneously using very small amounts of analytes. Here we show that carbohydrate microarrays are multifunctional tools for plant research and can be used to map glycan populations across large numbers of samples to screen antibodies, carbohydrate binding proteins, and carbohydrate binding modules and to investigate enzyme activities.