Identification of (L)-3-hydroxykynurenine O-sulfate in the buccal gland secretion of the parasitic lamprey, Lethenteron japonicum.
Parasitic lampreys are known to secrete proteins having anticoagulant and vasodilator activities from the buccal glands during feeding on their host's blood. However, small molecules in the secretion have never been explored in detail. We examined the secretion of Japanese liver lamprey (Lethenteron japonicum) for small molecules and found an intensely fluorescent substance upon gel filtration. After purification by anion-exchange chromatography and reversed-phase HPLC, structure of the compound was determined to be L-3-hydroxykynurenine O-sulfate by NMR- and UV-spectrometry, complemented with enzymatic and chemical degradation. In vertebrates, the sulfate ester of 3-hydroxykynurenine is a compound that has been regarded as a urinary metabolite of tryptophan but not reported from normal tissues to date. Although the function of this molecule in the buccal glands remains to be elucidated, it is remarkable that the same substance was described in 1960s from two species of blood-sucking insects, Rhodnius prolixus and Triatoma infestans, suggesting its potential role in blood-feeding.
Department of Biology, Faculty of Science and Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan. sodani@bio.sc.niigata-u.ac.jp
Shoji
S
Odani
Naoko
N
Ito
Mai
M
Hasegawa
Toshio
T
Uchiumi
Sumihiro
S
Hase
D000818:Animals; D007737:Kynurenine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D007798:Lampreys; D012470:Salivary Glands, Minor / Q000737:chemistry* / Q000378:metabolism
D007737:Kynurenine