1H, 15N and 13C assignments and secondary structure of the EGF‐like module pair 3–4 from vitamin K‐dependent protein S

FEBS Letters

Drakenberg, Torbjörn²  Stenberg, Yvonne¹  Evenäs, Johan²  Muranyi, Andreas²  Stenflo, Johan¹ 

[1] Clinical Chemistry, Lund University, University Hospital Malmö, S-205 02 Malmö, Sweden;Physical Chemistry 2, Lund University, P.O. Box 124, S-221 00 Lund, Sweden

关键词: Assignment;    Blood coagulation;    Calcium-binding epidermal growth factor-like module;    Protein S;   

DOI  :  10.1016/S0014-5793(00)01636-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Vitamin K-dependent protein S, which is a cofactor for activated protein C and thus important for down-regulation of the coagulation cascade, contains several Ca²⁺-binding sites with unusually high affinity. The 89 amino acid fragment constituting the third and fourth epidermal growth factor-like (EGF) modules of protein S is the smallest fragment that retains high-affinity Ca²⁺ binding and is therefore useful for investigating the structural basis of this property. Heteronuclear multidimensional nuclear magnetic resonance experiments were used to obtain extensive assignments of the ¹H, ¹⁵N and ¹³C resonances of the module pair with one Ca²⁺ bound in EGF 4. In addition, nearly complete assignments of the ¹H resonances of the isolated Ca²⁺-free EGF 3 module were obtained. The assignment process was complicated by broadening of several resonances, spectral heterogeneity caused by cis-trans isomerisation of the peptide bond preceding Pro-168, and dimerisation. Analysis of weighted average secondary chemical shifts, ³ J _HNHα coupling constants, and NOE connectivities suggest that both EGF modules in this fragment adhere to the classical secondary structure of EGF modules, consisting of one major and one minor anti-parallel β-sheet.

【 授权许可】

Unknown