Thiamin Is Decomposed Due to Anaphe spp. Entomophagy in Seasonal Ataxia Patients in Nigeria

Autor: Hiromu Akai, Hideki Okazaki, Takahiro Nishimune, Yoshihiro Watanabe
Rok vydání: 2000
Předmět:
Zdroj: The Journal of Nutrition. 130:1625-1628
ISSN: 0022-3166
DOI: 10.1093/jn/130.6.1625
Popis: A fairly high activity of a relatively heat-resistant thiaminase was detected and characterized from the pupae of an African silkworm Anaphe spp. which had been the putative cause of a seasonal ataxia and impaired consciousness in Nigerians. The thiaminase in the buffer extract of Anaphe pupae was type I (thiamin: base 2-methyl-4-aminopyrimidine methyl transferase EC 2.5.1.2), and the optimal temperature and pH were 70 degrees C and 8.0-8.5, respectively. Based on gel filtration chromatography, the molecules were estimated to be 200 kDa. Second substrates which could be utilized by the thiaminase were pyridoxine, amino acids, glutathione, taurine and 4-aminopyridine. Thiamin phosphate esters were inactive as substrates. This is the first report describing an insect thiaminase. Our results indicate the necessity of thorough heat treatment for the detoxification of the African silkworm, making the worm a safe source of high-quality protein.
Databáze: OpenAIRE