Adverse effects of Alport syndrome-related Gly missense mutations on collagen type IV: Insights from molecular simulations and experiments.

Jingjie Yeo, Yimin Qiu, Gang Seob Jung, Yong-Wei Zhang, Markus J Buehler, David L Kaplan

Journal: Biomaterials 2021;240():119857

PMID: 32085975

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Abstract

Patients with Alport syndrome (AS) exhibit blood and elevated protein levels in their urine, inflamed kidneys, and many other abnormalities. AS is attributed to mutations in type IV collagen genes, particularly glycine missense mutations in the collagenous domain of COL4A5 that disrupt common structural motifs in collagen from the repeat (Gly-Xaa-Yaa) amino acid sequence. To characterize and elucidate the molecular mechanisms underlying how AS-related mutations perturb the structure and function of type IV collagen, experimental studies and molecular simulations were integrated to investigate the structure, stability, protease sensitivity, and integrin binding affinity of collagen-like proteins containing amino acid sequences from the α5(IV) chain and AS-related Gly missense mutations. We show adverse effects where (i) three AS-related Gly missense mutations significantly reduced the structural stability of the collagen in terms of decreased melting temperatures and calorimetric enthalpies, in conjunction with a collective drop in the external work needed to unfold the peptides containing mutation sequences; (ii) due to local unwinding around the sites of mutations, these triple helical peptides were also degraded more rapidly by trypsin and chymotrypsin, as these enzymes could access the collagenous triple helix more easily and increase the number of contacts; (iii) the mutations further abolished the ability of the recombinant collagens to bind to integrins and greatly reduced the binding affinities between collagen and integrins, thus preventing cells from adhering to these mutants. Our unified experimental and computational approach provided underlying insights needed to guide potential therapies for AS that ameliorate the adverse effects from AS disease onset and progression.

Address: Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA; Laboratory for Atomistic and Molecular Mechanics (LAMM), Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Institute of High Performance Computing, A*STAR, 1 Fusionopolis Way, Singapore 138632, Singapore; Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA.; Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA; National Biopesticide Engineering Technology Research Center, Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan, 430064, PR China.; Laboratory for Atomistic and Molecular Mechanics (LAMM), Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.; Institute of High Performance Computing, A*STAR, 1 Fusionopolis Way, Singapore 138632, Singapore.; Laboratory for Atomistic and Molecular Mechanics (LAMM), Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Electronic address: [email protected].; Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA. Electronic address: [email protected].

DOI: 10.1016/j.biomaterials.2020.119857

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MeSH Terms: Amino Acid Substitution, Collagen Type IV, Glycine, Humans, Mutation, Missense, Nephritis, Hereditary