Anderson R, Huang Y
Department of Microbiology and Infectious Diseases, University of Calgary, Alberta, Canada.
J Bacteriol. 1992 Nov;174(22):7168-73. doi: 10.1128/jb.174.22.7168-7173.1992.
Deinococcus radiodurans contains novel phospholipids of which the structures of three have been previously described. These three lipids contain both fatty acids and alkylamines. Both the fatty acid and alkylamine constituents were found to be composed of a mixture of species, of which C15, C16, and C17 saturated and monounsaturated alkyl chains predominated. Alkylamines contained a relatively higher proportion of saturated species. Progression of bacterial growth through the mid-log to stationary phases was accompanied by an increase in the proportions of C15 and C17 alkyl chains in both fatty acid and alkylamine constituents. Radiolabeled palmitic acid was found to be rapidly incorporated into both fatty acid and alkylamine components of phosphatidylglyceroylalkylamine, which is the precursor of the more-complex phosphoglycolipids found in major amounts in D. radiodurans. After culturing D. radiodurans in the presence of a mixture of palmitic acids labeled with 14C and 3H in the 1 and 9,10 positions, respectively, the same 14C/3H ratio was recovered in both fatty acid and alkylamine constituents, strongly suggesting that alkylamines are derived from intact fatty acids rather than by a de novo pathway. The results identify a novel product of fatty acid metabolism which has not to date been observed in any other organism.
耐辐射球菌含有新型磷脂,其中三种的结构先前已被描述。这三种脂质都含有脂肪酸和烷基胺。发现脂肪酸和烷基胺成分均由多种物质的混合物组成,其中C15、C16和C17饱和及单不饱和烷基链占主导。烷基胺中饱和物质的比例相对较高。细菌从对数中期生长到稳定期的过程中,脂肪酸和烷基胺成分中C15和C17烷基链的比例都会增加。发现放射性标记的棕榈酸能迅速掺入磷脂酰甘油酰烷基胺的脂肪酸和烷基胺成分中,磷脂酰甘油酰烷基胺是耐辐射球菌中大量存在的更复杂磷酸糖脂的前体。在分别用14C和3H标记在1位和9,10位的棕榈酸混合物培养耐辐射球菌后,脂肪酸和烷基胺成分中回收的14C/3H比率相同,这有力地表明烷基胺源自完整的脂肪酸而非从头合成途径。这些结果确定了一种脂肪酸代谢的新产物,迄今为止在任何其他生物体中都未观察到。