Low Resolution Structure Determination Shows Procollagen C-Proteinase Enhancer to be an Elongated Multidomain Glycoprotein

Simonetta Bernocco,Barry M Steiglitz,Dmitri I Svergun,Maxim V Petoukhov,Florence Ruggiero,Sylvie Ricard-Blum,Christine Ebel,Christophe Geourjon,Gilbert Deléage,Bernard Font,Denise Eichenberger,Daniel S Greenspan,David J.S Hulmes

doi:10.1074/jbc.m210857200

Simonetta Bernocco, Barry M Steiglitz + Show 11 more

Open Access

https://doi.org/10.1074/jbc.m210857200

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Abstract

Procollagen C-proteinase enhancer (PCPE) is an extracellular matrix glycoprotein that can stimulate the action of tolloid metalloproteinases, such as bone morphogenetic protein-1, on a procollagen substrate, by up to 20-fold. The PCPE molecule consists of two CUB domains followed by a C-terminal NTR (netrin-like) domain. In order to obtain structural insights into the function of PCPE, the recombinant protein was characterized by a range of biophysical techniques, including analytical ultracentrifugation, transmission electron microscopy, and small angle x-ray scattering. All three approaches showed PCPE to be a rod-like molecule, with a length of approximately 150 A. Homology modeling of both CUB domains and the NTR domain was consistent with the low-resolution structure of PCPE deduced from the small angle x-ray scattering data. Comparison with the low-resolution structure of the procollagen C-terminal region supports a recently proposed model (Ricard-Blum, S., Bernocco, S., Font, B., Moali, C., Eichenberger, D., Farjanel, J., Burchardt, E. R., van der Rest, M., Kessler, E., and Hulmes, D. J. S. (2002) J. Biol. Chem. 277, 33864-33869) for the mechanism of action of PCPE.

Highlights

Procollagen C-proteinase enhancer (PCPE) is an extracellular matrix glycoprotein that can stimulate the action of tolloid metalloproteinases, such as bone morphogenetic protein-1, on a procollagen substrate, by up to 20fold
In PCPE, the CUB domains bind to the C-propeptide region of fibrillar procollagens [9], as well as elsewhere in the procollafound in complement subcomponents Clr/Cls, Uegf, and BMP-1; mTLD, mammalian tolloid; mTLL, mammalian tolloid-like; NTR, netrin-like; small angle x-ray scattering (SAXS), small angle X-ray scattering; TIMP, tissue inhibitor of metalloproteinases
The elongated shape deduced from analytical ultracentrifugation was confirmed by small angle x-ray scattering, which produced low-resolution models for the three-dimensional structure of the molecule

Summary

Introduction

Procollagen C-proteinase enhancer (PCPE) is an extracellular matrix glycoprotein that can stimulate the action of tolloid metalloproteinases, such as bone morphogenetic protein-1, on a procollagen substrate, by up to 20fold. Homology modeling of both CUB domains and the NTR domain was consistent with the low-resolution structure of PCPE deduced from the small angle x-ray scattering data.

Results

Conclusion