Siard T J, Katze J R, Farkas W R
University of Tennessee College of Veterinary Medicine, Knoxville 37901-1071.
Neurochem Res. 1989 Nov;14(11):1159-64. doi: 10.1007/BF00965624.
Pig brain tRNA was assayed for the presence of queuosine in the first position of the anticodon for each of the Q-family of tRNAs (aspartyl, asparaginyl, histidyl and tyrosyl). The brain tRNA was aminoacylated with each of the four amino acids and the aminoacylated tRNA's analyzed by RPC-5 chromatography. The results of this study show that for all four tRNAs of the family, queuine is substituted for guanine in virtually 100% of the anticodons. Therefore, it can be concluded that queuine is able to cross the blood-brain barrier and that brain contains guanine-queuine tRNA transglycosylase, the enzyme responsible for the excision of guanine from the original transcripts of these tRNAs and insertion of queuine. The determination of whether the tRNA contained queuine was made from the elution profile of the RPC-5 chromatograms and the results confirmed by a change in the RPC-5 elution profile when the tRNAs were reacted with BrCN or NaIO4.
对猪脑tRNA进行检测，以确定在Q族tRNA（天冬氨酰基、天冬酰胺基、组氨酰基和酪氨酰基）反密码子的第一位是否存在queuosine。用这四种氨基酸中的每一种对脑tRNA进行氨酰化，并通过RPC - 5色谱法分析氨酰化的tRNA。这项研究的结果表明，对于该家族的所有四种tRNA，在几乎100%的反密码子中，鸟嘌呤被queuine取代。因此，可以得出结论，queuine能够穿过血脑屏障，并且脑中含有鸟嘌呤 - queuine tRNA转糖基酶，该酶负责从这些tRNA的原始转录本中切除鸟嘌呤并插入queuine。根据RPC - 5色谱图的洗脱图谱确定tRNA是否含有queuine，并且当tRNA与溴化氰或高碘酸钠反应时，RPC - 5洗脱图谱的变化证实了结果。
