Finkenwirth Friedrich, Kirsch Franziska, Eitinger Thomas
Institut für Biologie/Mikrobiologie; Humboldt-Universität zu Berlin; Berlin, Germany.
Bioengineered. 2014 Mar-Apr;5(2):129-32. doi: 10.4161/bioe.26887. Epub 2013 Nov 5.
Biotin is an essential cofactor of carboxylase enzymes in all kingdoms of life. The vitamin is produced by many prokaryotes, certain fungi, and plants. Animals depend on biotin uptake from their diet and in humans lack of the vitamin is associated with serious disorders. Many aspects of biotin metabolism, uptake, and intracellular transport remain to be elucidated. In order to characterize the activity of novel biotin transporters by a sensitive assay, an Escherichia coli strain lacking both biotin synthesis and its endogenous high-affinity biotin importer was constructed. This strain requires artificially high biotin concentrations for growth. When only trace levels of biotin are available, it is viable only if equipped with a heterologous high-affinity biotin transporter. This feature was used to ascribe transport activity to members of the BioY protein family in previous work. Here we show that this strain together with its parent is also useful as a diagnostic tool for wide-concentration-range bioassays.
生物素是所有生命王国中羧化酶的必需辅助因子。这种维生素由许多原核生物、某些真菌和植物产生。动物依赖从饮食中摄取生物素，在人类中，缺乏这种维生素与严重疾病有关。生物素代谢、摄取和细胞内运输的许多方面仍有待阐明。为了通过灵敏的测定法表征新型生物素转运蛋白的活性，构建了一种既缺乏生物素合成又缺乏其内源性高亲和力生物素转运体的大肠杆菌菌株。该菌株需要人为高浓度的生物素来生长。当只有微量生物素可用时，只有配备异源高亲和力生物素转运体时它才能存活。在先前的工作中，这一特性被用于将转运活性归因于BioY蛋白家族的成员。在这里，我们表明该菌株及其亲本也可用作宽浓度范围生物测定的诊断工具。
