title: Purification and functional characterization of thermostable 5-aminolevulinic acid synthases.
abstract: OBJECTIVE
  As 5-aminolevulinic acid synthase (ALAS), the key enzyme for 5-aminolevulinic acid (ALA) synthesis, is unstable, we have sought to find thermostable ALASs from thermophilic organisms.
  
  
  RESULTS
  Three ALASs from thermophiles Geobacillus thermoglucosidasius (GT-ALAS), Laceyella sacchari (LS-ALAS) and Pseudomonas alcaliphila (PA-ALAS) were purified and characterized. All enzymes were more stable than two previously studied ALASs from Rhodopseudomonas palustris and Rhodobacter sphaeroides. There was almost no activity change after 60 h at 37 °C for the three thermostable enzymes. This contrasts with the other two enzymes which lost over 90 % activities in just 1 h. Furthermore, the specific activity of LS-ALAS (7.8 U mg(-1)) was also higher than any previously studied ALASs.
  
  
  CONCLUSIONS
  Thermostable ALASs were found in thermophilic organisms and this paves the way for developing cell free processes for enzymatic production of ALA from bulk chemicals succinate and glycine.
authors: School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.|Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, People's Republic of China.
authors: Qinglong
authors: Q
authors: Meng
authors: Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, People's Republic of China.
authors: Yanfei
authors: Y
authors: Zhang
authors: Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, People's Republic of China.
authors: Chunling
authors: C
authors: Ma
authors: Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, People's Republic of China. ma_hw@tib.cas.cn.
authors: Hongwu
authors: H
authors: Ma
authors: School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
authors: Xueming
authors: X
authors: Zhao
authors: School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
authors: Tao
authors: T
authors: Chen
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D000622:Aminolevulinic Acid / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D006358:Hot Temperature; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D000622:Aminolevulinic Acid; D000624:5-Aminolevulinate Synthetase
keywords: 5-Aminolevulinic acid; 5-Aminolevulinic acid synthase; Enzyme purification; Thermostability