MT1-MMP-TIMP-1 complex: Difference between revisions
No edit summary |
No edit summary |
||
| Line 10: | Line 10: | ||
The human matrix metalloproteinases (MMPs) family comprises a large group of structurally homologous zinc-dependent endopeptidases (''e.g.'' <scene name='MT1-MMP-TIMP-1_complex/Cv2/9'>membrane type-1 matrix metalloproteinase (MT1-MMP)</scene> <font color='darkmagenta'><b>(darkmagenta)</b></font> and <scene name='MT1-MMP-TIMP-1_complex/Cv/14'>membrane type-3 matrix metalloproteinase (MT3-MMP)</scene> <font color='magenta'><b>(magenta)</b></font>, <scene name='MT1-MMP-TIMP-1_complex/Cv2/10'>click to see structural comparison</scene>) that perform a wide variety of biological roles. In general, the MMPs are inhibited unselectively by all four known tissue inhibitors of metalloproteinases (TIMPs 1-4) which have 40-50% sequence identity. For example, <scene name='MT1-MMP-TIMP-1_complex/Cv/14'>membrane type-3 matrix metalloproteinase (MT3-MMP)</scene> can form complex with <scene name='MT1-MMP-TIMP-1_complex/Cv/12'>wild-type TIMP-1</scene> ([[1uea]], <font color='orange'><b>colored orange</b></font>). <scene name='MT1-MMP-TIMP-1_complex/Cv/13'>The WT-TIMP-1 binding interface</scene> <font color='cyan'><b>(cyan)</b></font> is mainly composed of the N-terminal segment that approaches the active site, the AB loop (Thr33-Tyr35), the CD loop (Ala65-Cys70), and the EF loop (Thr97-Ser100). The pivotal residue, threonine 98 (Thr98), is shown as <font color='red'><b>red sticks</b></font>. In general, <scene name='MT1-MMP-TIMP-1_complex/Cv1/2'>five main chain hydrogen bonds</scene> (Cys1-Ser68, Val69-Met66, Gly71-Met66, Cys70-Glu67, and Cys70-Thr98) are intimately involved in the conformational stability of TIMP binding interface when bound to MMP. | The human matrix metalloproteinases (MMPs) family comprises a large group of structurally homologous zinc-dependent endopeptidases (''e.g.'' <scene name='MT1-MMP-TIMP-1_complex/Cv2/9'>membrane type-1 matrix metalloproteinase (MT1-MMP)</scene> <font color='darkmagenta'><b>(darkmagenta)</b></font> and <scene name='MT1-MMP-TIMP-1_complex/Cv/14'>membrane type-3 matrix metalloproteinase (MT3-MMP)</scene> <font color='magenta'><b>(magenta)</b></font>, <scene name='MT1-MMP-TIMP-1_complex/Cv2/10'>click to see structural comparison</scene>) that perform a wide variety of biological roles. In general, the MMPs are inhibited unselectively by all four known tissue inhibitors of metalloproteinases (TIMPs 1-4) which have 40-50% sequence identity. For example, <scene name='MT1-MMP-TIMP-1_complex/Cv/14'>membrane type-3 matrix metalloproteinase (MT3-MMP)</scene> can form complex with <scene name='MT1-MMP-TIMP-1_complex/Cv/12'>wild-type TIMP-1</scene> ([[1uea]], <font color='orange'><b>colored orange</b></font>). <scene name='MT1-MMP-TIMP-1_complex/Cv/13'>The WT-TIMP-1 binding interface</scene> <font color='cyan'><b>(cyan)</b></font> is mainly composed of the N-terminal segment that approaches the active site, the AB loop (Thr33-Tyr35), the CD loop (Ala65-Cys70), and the EF loop (Thr97-Ser100). The pivotal residue, threonine 98 (Thr98), is shown as <font color='red'><b>red sticks</b></font>. In general, <scene name='MT1-MMP-TIMP-1_complex/Cv1/2'>five main chain hydrogen bonds</scene> (Cys1-Ser68, Val69-Met66, Gly71-Met66, Cys70-Glu67, and Cys70-Thr98) are intimately involved in the conformational stability of TIMP binding interface when bound to MMP. | ||
<scene name='MT1-MMP-TIMP-1_complex/Cv2/9'>Membrane type-1 matrix metalloproteinase (MT1-MMP)</scene> <font color='darkmagenta'><b>(darkmagenta)</b></font> also forms complex with <scene name='MT1-MMP-TIMP-1_complex/Cv2/11'>wild-type TIMP-1</scene> ([[2j0t]], <font color='orange'><b>colored orange</b></font>), producing <scene name='MT1-MMP-TIMP-1_complex/Cv2/12'>similar hydrogen bond network in the WT TIMP-1 binding interface</scene> as well as <scene name='MT1-MMP-TIMP-1_complex/Cv2/13'>in the case with MT3-MMP</scene>. This network of hydrogen bonds stabilizes the CD and EF loops that compose the binding interface. Importantly, the <scene name='MT1-MMP-TIMP-1_complex/Cv2/14'>hydrogen bond between Cys1 and Ser68 may position the amino and carboxyl groups of Cys1 to effectively coordinate the Zn2+ ion</scene>. MT1-MMP is unique since even though is exhibits high structural homology to all MMPs, it is not inhibited by TIMP-1, <scene name='MT1-MMP-TIMP-1_complex/Cv3/1'>but is inhibited by the structural homologous TIMP-2</scene> ([[1bqq]]). | <scene name='MT1-MMP-TIMP-1_complex/Cv2/9'>Membrane type-1 matrix metalloproteinase (MT1-MMP)</scene> <font color='darkmagenta'><b>(darkmagenta)</b></font> also forms complex with <scene name='MT1-MMP-TIMP-1_complex/Cv2/11'>wild-type TIMP-1</scene> ([[2j0t]], <font color='orange'><b>colored orange</b></font>), producing <scene name='MT1-MMP-TIMP-1_complex/Cv2/12'>similar hydrogen bond network in the WT TIMP-1 binding interface</scene> as well as <scene name='MT1-MMP-TIMP-1_complex/Cv2/13'>in the case with MT3-MMP</scene>. This network of hydrogen bonds stabilizes the CD and EF loops that compose the binding interface. Importantly, the <scene name='MT1-MMP-TIMP-1_complex/Cv2/14'>hydrogen bond between Cys1 and Ser68 may position the amino and carboxyl groups of Cys1 to effectively coordinate the Zn2+ ion</scene>. However, this MT1-MMP-WT-TIMP-1 complex is not tight-binding. MT1-MMP is unique since even though is exhibits high structural homology to all MMPs, it is not inhibited by TIMP-1, <scene name='MT1-MMP-TIMP-1_complex/Cv3/1'>but is inhibited by the structural homologous TIMP-2</scene> ([[1bqq]]). <scene name='MT1-MMP-TIMP-1_complex/Cv2/15'>The single point mutation T98L</scene> (mutant TIMP-1 is colored in <span style="color:yellow;background-color:black;font-weight:bold;">yellow</span> with <font color='red'><b>T98L shown in red</b></font>) transformed TIMP-1 into a high affinity inhibitor of MT1-MMP ([[3ma2]]). The overall structures of the complexes of <font color='darkmagenta'><b>MT1-MMP</b></font>-<font color='orange'><b>WT-TIMP-1</b></font> and <font color='violet'><b>MT1-MMP</b></font>-<span style="color:yellow;background-color:black;font-weight:bold;">mutant-T98L-TIMP-1</span> are <scene name='MT1-MMP-TIMP-1_complex/Cv2/17'>relatively similar</scene>. Even the structure of <font color='magenta'><b>MT3-MMP</b></font>-<font color='orange'><b>WT-TIMP-1</b></font> is <scene name='MT1-MMP-TIMP-1_complex/Cv2/18'>similar to those of MT1-MMP-TIMP-1s</scene> (with <font color='orange'><b>wild-type</b></font> and <span style="color:yellow;background-color:black;font-weight:bold;">TIMP-1 T98L mutant</span>). Thus, mutation affected the instrinsic dynamics of the inhibitor rather than its structure, thereby facilitating the interaction. Statistical analysis of the <scene name='MT1-MMP-TIMP-1_complex/Cv2/15'>key hydrogen bond</scene> stabilities in the TIMP-1 T98L mutant reveals that the hydrogen bonds network in mutant form is significantly more stable than that in WT-TIMP-1. Thus, mutations that enhance hydrogen | ||
bond stability contribute to the stability of the bound-like, less flexible, conformation of TIMP-1, which eventually results in increasing binding affinity for MT1-MMP. | bond stability contribute to the stability of the bound-like, less flexible, conformation of TIMP-1, which eventually results in increasing binding affinity for MT1-MMP. | ||