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Molecular mechanism of type I collagen homotrimer resistance to mammalian collagenases.

Han S, Makareeva E, Kuznetsova NV, DeRidder AM, Sutter MB, Losert W, Phillips CL, Visse R, Nagase H, Leikin S - J. Biol. Chem. (2010)

Bottom Line: Similar MMP-1 binding to the two isoforms and similar cleavage efficiency of unwound alpha1(I) and alpha2(I) chains suggested increased stability and less efficient unwinding of the homotrimer triple helix at the collagenase cleavage site.The unwinding, necessary for placing individual chains inside the catalytic cleft of the enzyme, was the rate-limiting cleavage step for both collagen isoforms.Comparative analysis of the homo- and heterotrimer cleavage kinetics revealed that MMP-1 binding promotes stochastic helix unwinding, resolving the controversy between different models of collagenase action.

View Article: PubMed Central - PubMed

Affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.

ABSTRACT
Type I collagen cleavage is crucial for tissue remodeling, but its homotrimeric isoform is resistant to all collagenases. The homotrimers occur in fetal tissues, fibrosis, and cancer, where their collagenase resistance may play an important physiological role. To understand the mechanism of this resistance, we studied interactions of alpha1(I)(3) homotrimers and normal alpha1(I)(2)alpha2(I) heterotrimers with fibroblast collagenase (MMP-1). Similar MMP-1 binding to the two isoforms and similar cleavage efficiency of unwound alpha1(I) and alpha2(I) chains suggested increased stability and less efficient unwinding of the homotrimer triple helix at the collagenase cleavage site. The unwinding, necessary for placing individual chains inside the catalytic cleft of the enzyme, was the rate-limiting cleavage step for both collagen isoforms. Comparative analysis of the homo- and heterotrimer cleavage kinetics revealed that MMP-1 binding promotes stochastic helix unwinding, resolving the controversy between different models of collagenase action.

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Cleavage of the α1(I) and α2(I) chains in 1:1 mixture of mouse homo- and heterotrimers (0. 2 μm each) by 5.8 μm MMP-1(ΔC) combined with 11 μm MMP-1(E200A) at 25 °C.
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Figure 4: Cleavage of the α1(I) and α2(I) chains in 1:1 mixture of mouse homo- and heterotrimers (0. 2 μm each) by 5.8 μm MMP-1(ΔC) combined with 11 μm MMP-1(E200A) at 25 °C.

Mentions: We did not observe noticeable collagen cleavage by either MMP-1(ΔC) alone or MMP-1(E200A) alone within 6–8 h, as described previously (24, 33, 34). When 5.8 μm MMP-1(ΔC) was combined with 11 μΜ MMP-1(E200A), we observed ∼10 times faster chain cleavage in the heterotrimers than homotrimers (Fig. 4). The cleavage efficiency (fraction cleaved) of the α2(I) and α1(I) chains within the heterotrimers was similar, suggesting that the slower α1(I) chain cleavage in the homotrimers was related to the resistance of the latter to triple helix unwinding by MMP-1(E200A).


Molecular mechanism of type I collagen homotrimer resistance to mammalian collagenases.

Han S, Makareeva E, Kuznetsova NV, DeRidder AM, Sutter MB, Losert W, Phillips CL, Visse R, Nagase H, Leikin S - J. Biol. Chem. (2010)

Cleavage of the α1(I) and α2(I) chains in 1:1 mixture of mouse homo- and heterotrimers (0. 2 μm each) by 5.8 μm MMP-1(ΔC) combined with 11 μm MMP-1(E200A) at 25 °C.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2903388&req=5

Figure 4: Cleavage of the α1(I) and α2(I) chains in 1:1 mixture of mouse homo- and heterotrimers (0. 2 μm each) by 5.8 μm MMP-1(ΔC) combined with 11 μm MMP-1(E200A) at 25 °C.
Mentions: We did not observe noticeable collagen cleavage by either MMP-1(ΔC) alone or MMP-1(E200A) alone within 6–8 h, as described previously (24, 33, 34). When 5.8 μm MMP-1(ΔC) was combined with 11 μΜ MMP-1(E200A), we observed ∼10 times faster chain cleavage in the heterotrimers than homotrimers (Fig. 4). The cleavage efficiency (fraction cleaved) of the α2(I) and α1(I) chains within the heterotrimers was similar, suggesting that the slower α1(I) chain cleavage in the homotrimers was related to the resistance of the latter to triple helix unwinding by MMP-1(E200A).

Bottom Line: Similar MMP-1 binding to the two isoforms and similar cleavage efficiency of unwound alpha1(I) and alpha2(I) chains suggested increased stability and less efficient unwinding of the homotrimer triple helix at the collagenase cleavage site.The unwinding, necessary for placing individual chains inside the catalytic cleft of the enzyme, was the rate-limiting cleavage step for both collagen isoforms.Comparative analysis of the homo- and heterotrimer cleavage kinetics revealed that MMP-1 binding promotes stochastic helix unwinding, resolving the controversy between different models of collagenase action.

View Article: PubMed Central - PubMed

Affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.

ABSTRACT
Type I collagen cleavage is crucial for tissue remodeling, but its homotrimeric isoform is resistant to all collagenases. The homotrimers occur in fetal tissues, fibrosis, and cancer, where their collagenase resistance may play an important physiological role. To understand the mechanism of this resistance, we studied interactions of alpha1(I)(3) homotrimers and normal alpha1(I)(2)alpha2(I) heterotrimers with fibroblast collagenase (MMP-1). Similar MMP-1 binding to the two isoforms and similar cleavage efficiency of unwound alpha1(I) and alpha2(I) chains suggested increased stability and less efficient unwinding of the homotrimer triple helix at the collagenase cleavage site. The unwinding, necessary for placing individual chains inside the catalytic cleft of the enzyme, was the rate-limiting cleavage step for both collagen isoforms. Comparative analysis of the homo- and heterotrimer cleavage kinetics revealed that MMP-1 binding promotes stochastic helix unwinding, resolving the controversy between different models of collagenase action.

Show MeSH
Related in: MedlinePlus