title: [In vitro expression study of novel mutations in phenylalanine hydroxylase gene].
abstract: OBJECTIVE
  To study the in vitro expression of 6 novel missense mutations (R270G, P275A, F121L, A156P, E183G, I324N) and a previously described R408Q mutation of phenylalanine hydroxylase (PAH) gene and explore the genotype-phenotype correlation through comparison of protein levels and residual enzyme activities.
  
  
  METHODS
  Seven expression vectors containing PAH cDNA were constructed with a site-directed mutagenesis kit. The plasmids were extracted and sequenced to confirm the target mutations. pcDNA3.0 containing PAH cDNA was transfected into COS-7 cells and total proteins were extracted 48 h after transfection. The quantities of proteins and residual enzyme activities of the 7 mutants were assessed with the wild-type PAH gene as reference.
  
  
  RESULTS
  Relative quantities of PAH proteins for R270G, P275A, F121L, A156P, E183G, I324N and R408Q were 10.5%, 56.6%, 54.3%, 8.7%, 8.5%, 67.3% and 85.4%, respectively. The residual enzyme activities were 7.7%, 27.6%, 19.0%, 10.4%, 9.1%, 50.6% and 40.2%, respectively.
  
  
  CONCLUSIONS
  PAH residual enzyme activities of 7 PAH mutants were all significantly reduced.
authors: Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai 200092, P.R. China. gu_xf53@yahoo.com.cn.
authors: Xin-shun
authors: XS
authors: Zhang
authors: Xue-fan
authors: XF
authors: Gu
authors: Li-li
authors: LL
authors: Liang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D056726:Genetic Association Studies / Q000379:methods; D006801:Humans; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010651:Phenylalanine Hydroxylase / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D010651:Phenylalanine Hydroxylase