Domain structure and stability of human phenylalanine hydroxylase inferred from infrared spectroscopy

FEBS Letters

Arrondo, Jose Luis R²  Flatmark, Torgeir¹  Muga, Arturo²  Knappskog, Per M³  Chehin, Rosana²  Thorolfsson, Matthias¹  Martinez, Aurora¹ 

[1] Department of Biochemistry and Molecular Biology, University of Bergen, Arstadveien 19, N-5009 Bergen, Norway;Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain;Department of Medical Genetics, University of Bergen, Haukeland Hospital, N-5021 Bergen, Norway

关键词: Phenylalanine hydroxylase;    Deletion mutation;    Protein structure;    Protein stability;    Infrared;    hPAH;    human phenylalanine hydroxylase;    IR;    infrared;    MBP;    maltose binding protein;    TH;    tyrosine hydroxylase;    PKA;    cyclic AMP-dependent protein kinase;    wt-hPAH;    wild-type human phenylalanine hydroxylase;   

DOI  :  10.1016/S0014-5793(97)01596-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have studied the conformation and thermal stability of recombinant human phenylalanine hydroxylase (hPAH) and selected truncated forms, corresponding to distinct functional domains, by infrared spectroscopy. The secondary structure of wild-type hPAH was estimated to be 48% α-helix, 28% extended structures, 12% β-turns and 12% non-structured conformations. The catalytic C-terminal domain (residues 112–452) holds most of the regular secondary structure elements, whereas the regulatory N-terminal domain (residues 2–110) adopts mainly an extended and disordered, flexible conformation. Thermal stability studies of the enzyme forms indicate the existence of interactions between the two domains. Our results also demonstrate that the conformational events involved in the activation of hPAH by its substrate (L-Phe) are mainly related to changes in the tertiary/quaternary structure. The activating effect of phosphorylation, however, affects the secondary structure of the N-terminal domain of the protein.

【 授权许可】

Unknown