The solution structure and heme binding of the presequence of murine 5‐aminolevulinate synthase

FEBS Letters

Goodfellow, Brian J¹  Ferreira, Glória C³  Dias, Jorge S⁴  Wray, Victor²  Macedo, Anjos L⁴  Henklein, Peter⁵ 

[1] Departamento de Quı́mica, Universidade de Aveiro, 3810-193 Aveiro, Portugal;GBF, Mascheroder Weg 1, D-38124 Braunschweig, Germany;Department of Biochemistry and Molecular Biology, College of Medicine, Institute for Biomolecular Science, and H. Lee Moffitt Cancer Center and Research Institute, University of South Florida, Tampa, FL 33612-4799, USA;Departamento de Quı́mica, C.Q.F.B., Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2825-114 Caparica, Portugal;Institut für Biochemie Peptidsynthese, Charité, D-10098 Berlin, Germany

关键词: Heme binding;    5-Aminolevulinate synthase;    Nuclear magnetic resonance structure;    Presequence;    Target peptide;    ALAS;    5-aminolevulinate synthase;    psALAS;    ALAS presequence;    NOESY;    nuclear Overhauser effect spectroscopy;    TOCSY;    total correlation spectroscopy;    DQF-COSY;    double quantum filtered correlated spectroscopy;    TFE;    trifluoroethanol;    SDS;    sodium dodecyl sulfate;    CD;    circular dichroism spectroscopy;    TF;    target function;   

DOI  :  10.1016/S0014-5793(01)02818-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The mitochondrial import of 5-aminolevulinate synthase (ALAS), the first enzyme of the mammalian heme biosynthetic pathway, requires the N-terminal presequence. The 49 amino acid presequence transit peptide (psALAS) for murine erythroid ALAS was chemically synthesized, and circular dichroism and ¹H nuclear magnetic resonance (NMR) spectroscopies used to determine structural elements in trifluoroethanol/H₂O solutions and micellar environments. A well defined amphipathic α-helix, spanning L22 to F33, was present in psALAS in 50% trifluoroethanol. Further, a short α-helix, defined by A5–L8, was also apparent in the 26 amino acid N-terminus peptide, when its structure was determined in sodium dodecyl sulfate. Heme inhibition of ALAS mitochondrial import has been reported to be mediated through cysteine residues in presequence heme regulatory motifs (HRMs). A UV/visible and ¹H NMR study of hemin and psALAS indicated that a heme–peptide interaction occurs and demonstrates, for the first time, that heme interacts with the HRMs of psALAS.

【 授权许可】

Unknown