Maitin V, Athanasopoulos V, Rastall R A
School of Food Biosciences, The University of Reading, Whiteknights, PO Box 226, RG6 6AP, Reading, UK.
Appl Microbiol Biotechnol. 2004 Feb;63(6):666-71. doi: 10.1007/s00253-003-1416-2. Epub 2003 Aug 9.
Recombinant Penicillium citrinum alpha-1,2-mannosidase, expressed in Aspergillus oryzae, was employed to carry out regioselective synthesis of alpha- d-mannopyranosyl-(1-->2)- d-mannose. Yields (w/w) of 16.68% disaccharide, 3.07% trisaccharide and 0.48% tetrasaccharide were obtained, with alpha1-->2 linkages present at 98.5% of the total linkages formed. Non-specific alpha-mannosidase from almond was highly efficient in reverse hydrolysis and oligosaccharide yields of 45-50% were achieved. The products of the almond mannosidase were a mixture of disaccharides (30.75%, w/w), trisaccharides (12.26%, w/w) and tetrasaccharides (1.89%, w/w) with 1-->2, 1-->3 and 1-->6 isomers. alpha-1,2-linkage specific mannosidase from P. citrinum and alpha-1,6-linkage-specific mannosidase from Aspergillus phoenicis were used in combination to hydrolyse the respective linkages from the mixture of isomers, resulting in alpha- d-mannopyranosyl-(1-->3)- d-mannose in 86.4% purity. The synthesised oligosaccharides can potentially inhibit the adhesion of pathogens by acting as "decoys" of receptors of type-1 fimbriae carried by enterobacteria.
在米曲霉中表达的重组桔青霉α-1,2-甘露糖苷酶被用于进行α-d-甘露吡喃糖基-(1→2)-d-甘露糖的区域选择性合成。获得了产率（w/w）为16.68%的二糖、3.07%的三糖和0.48%的四糖，α1→2键占形成的总键数的98.5%。来自杏仁的非特异性α-甘露糖苷酶在逆水解方面效率很高，寡糖产率达到45 - 50%。杏仁甘露糖苷酶的产物是二糖（30.75%，w/w）、三糖（12.26%，w/w）和四糖（1.89%，w/w）的混合物，含有1→2、1→3和1→6异构体。将来自桔青霉的α-1,2-键特异性甘露糖苷酶和来自泡盛曲霉的α-1,6-键特异性甘露糖苷酶联合使用，从异构体混合物中水解各自的键，得到纯度为86.4%的α-d-甘露吡喃糖基-(1→3)-d-甘露糖。合成的寡糖可能通过充当肠道细菌携带的1型菌毛受体的“诱饵”来抑制病原体的粘附。
