Nagata Y, Fujiwara T, Kawaguchi-Nagata K, Fukumori Y, Yamanaka T
Department of Life Science, Himeji Institute of Technology, Hyogo, Japan.
Biochim Biophys Acta. 1998 Jan 8;1379(1):76-82. doi: 10.1016/s0304-4165(97)00084-6.
The occurrence of peptidyl D-amino acids in the aqueous soluble fractions was investigated in various eubacteria, some archaea and some eukaryotes. The contents of the D-enantiomers of serine, alanine, proline, glutamate (glutamine), aspartate (asparagine) and phenylalanine were determined with cell- and tissue-extracts, by means of acid hydrolysis and high-performance liquid chromatography. The rate of D-enantiomer (%, the ratio in molar concentration of a D-amino acid to the total of the D-amino acid and the corresponding L-amino acid) of alanine and glutamate were high in some Gram-positive eubacteria: 11.7% in Staphylococcus epidermidis and 10.3% in Streptococcus pyogenes for alanine, and 22.3% for glutamate in Bacillus YN-1. The D-glutamate content was also high (8.0%) in the Gram-negative eubacterium, Thiobacillus ferrooxidans. D-Aspartate was common, as was D-glutamate: the highest D-aspartate content was detected in an archaeum, Pyrobaculum islandicum (4.0%). However, the content of D-aspartate was low, 0.2-1.8% in most other bacteria. The presence of D-serine was shown in some organisms, but that of D-proline was scarce. The D-enantiomer of phenylalanine was not detected in any of the organisms examined. These results indicate that of the bacteria examined herein most Gram-negative and some Gram-positive eubacteria, as well as archaea contain only low levels of D-amino acids in the soluble peptidyl fraction, and the levels were comparable to those in eukaryotes examined. To our knowledge, the general presence of peptidyl D-amino acids in these organisms, especially archaea and eukaryotic cells including those from rat liver tissues, has been shown here for the first time.
研究了各种真细菌、一些古细菌和一些真核生物中水溶性组分中肽基D - 氨基酸的出现情况。通过酸水解和高效液相色谱法，测定了细胞和组织提取物中丝氨酸、丙氨酸、脯氨酸、谷氨酸（谷氨酰胺）、天冬氨酸（天冬酰胺）和苯丙氨酸的D - 对映体含量。在一些革兰氏阳性真细菌中，丙氨酸和谷氨酸的D - 对映体比例（%，D - 氨基酸与D - 氨基酸和相应L - 氨基酸总摩尔浓度的比值）较高：表皮葡萄球菌中丙氨酸为11.7%，化脓性链球菌中丙氨酸为10.3%，芽孢杆菌YN - 1中谷氨酸为22.3%。在革兰氏阴性真细菌氧化亚铁硫杆菌中，D - 谷氨酸含量也较高（8.0%）。D - 天冬氨酸和D - 谷氨酸一样常见：在古细菌冰岛嗜火菌中检测到最高的D - 天冬氨酸含量（4.0%）。然而，在大多数其他细菌中，D - 天冬氨酸含量较低，为0.2 - 1.8%。在一些生物体中显示存在D - 丝氨酸，但D - 脯氨酸很少。在所检测的任何生物体中均未检测到苯丙氨酸的D - 对映体。这些结果表明，在本文所检测的细菌中，大多数革兰氏阴性和一些革兰氏阳性真细菌以及古细菌在可溶性肽基组分中仅含有低水平的D - 氨基酸，其水平与所检测的真核生物相当。据我们所知，首次在此证明了这些生物体中，特别是古细菌和包括大鼠肝脏组织细胞在内的真核细胞中普遍存在肽基D - 氨基酸。
