Applications of gellan natural polymer microspheres in recombinant catechol-O-methyltransferase direct capture from a Komagataella pastoris lysate

Specific Six-Transmembrane Epithelial Antigen of the Prostate 1 Capture with Gellan Gum Microspheres: Design, Optimization and Integration

“…Nickel-, magnesium-and copper-crosslinked GG microspheres had also been previously reported with a spherical shape. However, the aforementioned microspheres presented clear rugosity, cavities and irregularities in their surface [35,36]. By comparison, calcium-crosslinked GG microspheres are far smoother, with no apparent pores, cavities or cracks (Figure 1D).…”

“…The obtained mean diameter was of 330.37 ± 11.38 µm. Nickel-crosslinked GG microspheres had been previously described with a mean diameter of 239.06 ± 5.43 µm [35]. Representative snapshots can be seen in Figure 1.…”

“…Calcium was chosen as it is the most widely used crosslinker for GG microspheres by researchers, with proven efficacy in drug delivery [43], immobilization of cells and enzymes [32,44] and degradation of pollutants [31]. Nickel was selected since our research group had previously demonstrated this ion yielded the best capture and purification results for COMT, through a similar GG batch method [35]. Indeed, because nickel-crosslinked GG microspheres had already been described elsewhere, they were excluded from further characterization.…”

“…When compared to nickel-crosslinked GG microspheres, the normalized ion percentage levels seem to differ nearly two-fold. Indeed, when comparing copper-, magnesium-, nickel-and calcium-crosslinked microspheres by crosslinker percentage, it seems that transition metals are incorporated in higher degrees than alkaline earth metals [35,36]. This stronger crosslinker concentration can induce the formation of a tighter mesh network, resulting in more compact microspheres, which can justify why nickel-crosslinked microspheres are smaller than calcium-crosslinked microspheres [45].…”

“…Indeed, GG-based materials have been shown to promote strong adsorption of small drug molecules [34]. Recently, our research group demonstrated that GG microspheres can efficiently capture soluble catechol-O-methyltransferase (COMT) [35] and plasmid DNA [36]. Current microsphere-based methods being developed for protein capture are mostly based on magnetic microspheres, which quickly enhance the complexity and cost of bioprocesses [37][38][39][40].…”