Author(s): LI Wentian, GONG Meixia, DAI Weihong, ZHANG Lei, WANG Wenjing, LIU Chaoliang, MENG Yan
Pages: 257-263
Year: 2014 Issue:  3
Journal: Acta Laser Biology Sinica
Keyword:  lem silkworm; sepiapterin reductase; tetrahydrobiopterin; prokaryotic expression; enzyme activity;
Abstract: Sepiapterin (SP)is contained in the integument of silkworm Bombyx mori mutant lemon (lem)in high con-centration.Sepiapterin reductase (SPR)is a key enzyme to catalyze SP to synthesize tetrahydrobiopterin (BH4).BH4 is an essential cofactor for aromatic acid hydroxylases,deficiency of which has been associated with many neuropsycho-logical disorders.We have cloned the SPR gene from B.mori (BmSpr)and made it known that BmSpr was responsible for the lem mutant phenotype.In this study,the recombinant plasmid pET-24b-BmSpr was transformed into different E. coli strains and the expression conditions of BmSpr were optimized in vitro.SDS-PAGE and western blot analyses showed that BmSpr could be expressed steadily in the optimized prokaryotic expression system.The results of enzymatic analyses indicated that BmSpr exhibited great activity to the substrate of SP.Findings in this research help to apply the expressed BmSpr to synthesize BH4 in vitro by using extracted SP from the lem mutant as substrate in the future.