Connaris S, Greenwell P
School of Biological and Health Sciences, University of Westminster, London, UK.
Glycoconj J. 1997 Nov;14(7):879-82. doi: 10.1023/a:1018554408558.
A range of protozoans were tested for the presence of glycosidases using p-nitrophenyl sugars as substrates. Some of the organisms were mucin dwellers whereas others were blood borne parasites. It had been hypothesized that glycosidase production would be significantly higher in the mucin dwellers. The results obtained demonstrated that the urogenital protozoans Tritrichomonas foetus and Trichomonas vaginalis produced a vast range of glycosidases which included those required for mucin breakdown. The gut dwelling protozoans Giardia lamblia and Entamoeba histolytica both produced beta-N-acetylglucosaminidase. G.lamblia also had detectable beta N-acetylgalactosaminidase activity, and small amounts of beta mannosidase were found in the extracts from E. histolytica. In contrast, little or no glycosidase activity was detected under the same experimental conditions in Leishmania donovani, Trypanosoma brucei or T. cruzi. The mucin dwelling protozoans all produce beta-N-acetylglucosaminidase but only the Trichomonads produced the range of enzymes required for complete breakdown of mucin. This seems to suggest that mucin breakdown is not a characteristic of all mucin dwelling protozoans.
以对硝基苯基糖为底物，对一系列原生动物进行了糖苷酶检测。其中一些生物体生活在黏蛋白中，而另一些则是血源寄生虫。据推测，生活在黏蛋白中的原生动物糖苷酶产量会显著更高。所得结果表明，泌尿生殖原生动物胎儿三毛滴虫和阴道毛滴虫产生了多种糖苷酶，包括分解黏蛋白所需的那些酶。肠道原生动物蓝氏贾第鞭毛虫和溶组织内阿米巴都产生β-N-乙酰氨基葡萄糖苷酶。蓝氏贾第鞭毛虫也具有可检测到的β-N-乙酰半乳糖胺酶活性，并且在溶组织内阿米巴的提取物中发现了少量的β-甘露糖苷酶。相比之下，在相同实验条件下，杜氏利什曼原虫、布氏锥虫或克氏锥虫几乎没有检测到糖苷酶活性。生活在黏蛋白中的原生动物都产生β-N-乙酰氨基葡萄糖苷酶，但只有毛滴虫产生了完全分解黏蛋白所需的一系列酶。这似乎表明，黏蛋白分解并非所有生活在黏蛋白中的原生动物的特征。
