TAILIEUCHUNG - Báo cáo khoa học: Structural characterization of Ca2+/CaM in complex with the phosphorylase kinase PhK5 peptide

Phosphorylase kinase (PhK) is a large hexadecameric enzyme consisting of four copies of four subunits: (abcd)4. An intrinsic calmodulin (CaM, the d subunit) binds directly to the cprotein kinase chain. The interaction site of CaM onchas been localized to a C-terminal extension of the kinase domain. Two 25-mer peptides derived from this region, PhK5 and PhK13, were identified previously as potential CaM-binding sites. | ềFEBS Journal Structural characterization of Ca2 CaM in complex with the phosphorylase kinase PhK5 peptide Atlanta G. Cook Louise N. Johnson and James M. McDonnell Laboratory of Molecular Biophysics Department of Biochemistry Oxford University UK Keywords calmodulin kinase regulation proteinprotein interaction NMR spectroscopy Correspondence J. M. McDonnell Laboratory of Molecular Biophysics Department of Biochemistry Oxford University South Parks Road Oxford OX1 3QU UK Fax 44 1865 275182 Tel 44 1865 275381 E-mail jim@ Present address EMBL Meyerhofstrasse 1 D-69117 Heidelberg Germany Received 7 December 2004 revised 23 January 2005 accepted 1 February 2005 doi Phosphorylase kinase PhK is a large hexadecameric enzyme consisting of four copies of four subunits aPyS 4. An intrinsic calmodulin CaM the Ỗ subunit binds directly to the c protein kinase chain. The interaction site of CaM on c has been localized to a C-terminal extension of the kinase domain. Two 25-mer peptides derived from this region PhK5 and PhK13 were identified previously as potential CaM-binding sites. Complex formation between Ca2 CaM with these two peptides was characterized using analytical gel filtration and NMR methods. NMR chemical shift perturbation studies showed that while PhK5 forms a robust complex with Ca2 CaM no interactions with PhK13 were observed. 15N relaxation characteristics of Ca2 CaM and Ca2 CaM PhK5 complexes were compared with the experimentally determined structures of several Ca2 CaM peptide complexes. Good fits were observed between Ca2 CaM PhK5 and three structures Ca2 CaM complexes with peptides from endothelial nitric oxide synthase with smooth muscle myosin light chain kinase and CaM kinase I. We conclude that the PhK5 site is likely to have a direct role in Ca2 -regulated control of PhK activity through the formation of a classical compact CaM complex. Phosphorylase kinase PhK is a Ca2 -regulated protein kinase that controls

• Báo cáo khoa học
• Report medicine
• traditional medicine
• scientific reports
• Structural biochemistry
• bacteria
• chemical reaction
• medical knowledge
• medical research
• analysis of cytoplasmic
• oxidation
• Crystal structure
• hemoglobin
• medicine
• cell proliferation
• breast cancer
• gastric cancer
• hormone medicine
• tumor cells
• biochemical studies
• environmental medicine