TY - JOUR
T1 - Fragmentation of fibronectin by inherent autolytic and matrix metalloproteinase activities
AU - Steffensen, Bjorn
AU - Chen, Zhihua
AU - Pal, Sanjay
AU - Mikhailova, Margarita
AU - Su, Jianrong
AU - Wang, Yao
AU - Xu, Xiaoping
N1 - Funding Information:
We greatly appreciate the constructive recommendations to the experiments by Dr. Robert J. Klebe, Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, and Dr. Susan Weintraub at the UTHSCSA Mass Spectrometry Laboratory for guidance in sample analyses and data interpretation. Supported by grants DE017139 , DE016312 , DE014236 , and DE018135 from the National Institutes of Health, Bethesda, MD .
PY - 2011/1
Y1 - 2011/1
N2 - Fibronectin (FN) purified by gelatin affinity chromatography is unstable and undergoes fragmentation. The cleavage has been ascribed to inherent autolytic protease activities as well as co-purified matrix metalloproteinases (MMP). Understanding the mechanism by which the proteolysis of FN occurs is important, because the FN fragments have biological activities that differ from those of intact FN. Having excluded contributions of other plasma-derived proteases, the present experiments demonstrated that cleavage of FN by MMP-2 to distinct fragments occurred in synergy with inherent FN activities. Limited heat treatment of FN at 56 °C for 30. min inactivated the inherent protease activities sharply reducing autolysis of FN in a manner similar to that seen in the presence of serine proteinase inhibitors. Heat treatment did not alter cell attachment to FN, but significantly increased the susceptibility of FN to enzymatic cleavage by MMP-2. The carboxyl-terminal hemopexin-like domain (PEX) of MMP-2 was shown to possess critical exodomain properties required for the interactions of MMP-2 with FN, and FN was cleaved at a significantly reduced rate by an MMP-2 variant with deletion of PEX. Verifying the specificity of interactions, isolated PEX competed FN cleavage by MMP-2 in a concentration-dependent manner. These results have further elucidated the synergistic contributions of inherent autolytic serine protease-like activities and MMP-2 to fragmentation of FN and provide the rationale and basis for modified preparation and handling of FN used in biological research.
AB - Fibronectin (FN) purified by gelatin affinity chromatography is unstable and undergoes fragmentation. The cleavage has been ascribed to inherent autolytic protease activities as well as co-purified matrix metalloproteinases (MMP). Understanding the mechanism by which the proteolysis of FN occurs is important, because the FN fragments have biological activities that differ from those of intact FN. Having excluded contributions of other plasma-derived proteases, the present experiments demonstrated that cleavage of FN by MMP-2 to distinct fragments occurred in synergy with inherent FN activities. Limited heat treatment of FN at 56 °C for 30. min inactivated the inherent protease activities sharply reducing autolysis of FN in a manner similar to that seen in the presence of serine proteinase inhibitors. Heat treatment did not alter cell attachment to FN, but significantly increased the susceptibility of FN to enzymatic cleavage by MMP-2. The carboxyl-terminal hemopexin-like domain (PEX) of MMP-2 was shown to possess critical exodomain properties required for the interactions of MMP-2 with FN, and FN was cleaved at a significantly reduced rate by an MMP-2 variant with deletion of PEX. Verifying the specificity of interactions, isolated PEX competed FN cleavage by MMP-2 in a concentration-dependent manner. These results have further elucidated the synergistic contributions of inherent autolytic serine protease-like activities and MMP-2 to fragmentation of FN and provide the rationale and basis for modified preparation and handling of FN used in biological research.
KW - Autolysis
KW - Cell attachment
KW - Fibronectin
KW - MMP
KW - Matrix metalloproteinase
KW - Proteolysis
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U2 - 10.1016/j.matbio.2010.09.004
DO - 10.1016/j.matbio.2010.09.004
M3 - Article
C2 - 20932906
AN - SCOPUS:78951486815
VL - 30
SP - 34
EP - 42
JO - Collagen and Related Research
JF - Collagen and Related Research
SN - 0945-053X
IS - 1
ER -