α-Mannosidases from the Digestive Fluid of Rhynchophorus Palmarum Larvae as Novel Biocatalysts for Transmannosylation Reactions

Abstract

Two biological fluids, namely hemolymph and digestive fluid from the larval stage of Rhynchophorus palmarum Linneaus, a serious pest in agroecosystem exploiting oil palm, were screened for hydrolytic activities, by the use of synthetic and natural glycoside substrates. Several exo and endoglycosidase activities were observed but, the interesting alpha-mannosidase activity (0.41 +/- 0.04 UI) had attracted our attention. So, we have previously demonstrated that this activity harbours four distinctive alpha-mannosidase isoforms named RpltM, RplM1, RplM2 and RplM3. We have extended this work to determine the ability of these enzymes to catalyze synthesis reactions. Finally, we have revealed that, alpha-mannosidases from the digestive fluid of R. palmarum larvae catalyze transmannosylation reactions. The stability of the enzymes and the optimization of the transfer product yield were studied as functions of pH, enzyme unit, starting concentration of donor or acceptor and time. It was shown that, in experimental optimum conditions, average yields of 12.34 +/- 0.75, 12.15 +/- 0.79, 5.59 +/- 0.35 and 8.43 +/- 0.50% were obtained for the alpha-mannosidases RpltM, RplM1, RplM2 and RplM3, respectively. On the basis of this work, alpha-mannosidases from the digestive fluid of Rhynchophorus palmarum larvae appear to be a valuable tool for the preparation of neoglycoconjugates.

Lipase Activity in the Larval Midgut of Rhynchophorus palmarum: Biochemical Characterization and the Effects of Reducing Agents

“…The soluble and membrane-bound digestive lipases of the midgut of P. brassicae showed an optimal pH of 8 and 10, respectively [ 22 ]. For R. palmarum palm weevils, digestive juices showed an optimum pH for β-glucosidase and α-mannosidase activity between 4.5 and 6.0 [ 11 , 12 ]. We observed a decrease of 20–25% in activity at salt concentrations higher than 0.5 M ( Figure 3 A).…”

“…R. palmarum have been reported as one of the most important pests on commercial palm plantations [ 10 ] and there are some studies in the literature about their digestive processes and their energetic metabolisms. Bédikou et al [ 11 ] showed α-mannosidase activities from the digestive fluids of R. palmarum larvae. Biochemical characterizations for specific β-glucosidases from the digestive fluids of the larvae from R. palmarum have been performed [ 12 ].…”

Structural features underlying prebiotic activity of conventional and potential prebiotic oligosaccharides in food and health

“…Enzymes are expensive components in downstream processing, and immobilization technology (both enzyme and living cells) is gaining ground in the production of OS (Li, Xiao, Lu, & Li, ). In addition to all the various sources of currently available oligosaccharides, novel prebiotics are being developed by modulating oligosaccharide structure via transfructosylation (Corzo‐Martínez, García‐Campos, Montilla, & Moreno, ), transgalactosylation (Sakaki et al, ) and transmannosylation (Bédikou et al, ). Modulation of the prebiotic activity can also be possible through the use of OS mixtures with the appropriate OS in their respective optimum ratios (Guerrero et al, ).…”

Biochemical characterization of phosphatase,  -galactosidase and  -mannosidase activities of seeds of an oleaginous cucurbit:<i> Lagenaria siceraria </i>(Molina) Standl blocky-fruited cultivar

“…In this respect, any loss of enzymatic activity is irremediably followed by metabolic disorders (Noble & Bovey, 1997;Kranz et al, 2007). Interest in enzymes also lies in their usages for various biotechnological purposes (Oehmig et al, 2007;Betancor et al, 2008;Bédikou et al, 2009a). For specific examples, enzymatic hydrolysis of lactose by  -galactosidases in production of low lactose milk (and dairy products made from it) is essential for lactose intolerant patients (Dwevedi & Kayastha, 2009).…”