Structural characterization of V57D and V57P mutants of human cystatin C, an amyloidogenic protein

Marta Orlikowska, Aneta Szymańska, Dominika Borek, Zbyszek Otwinowski, Piotr Skowron, Elzbieta Jankowska

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

Wild-type human cystatin C (hCC wt) is a low-molecular-mass protein (120 amino-acid residues, 13343Da) that is found in all nucleated cells. Physiologically, it functions as a potent regulator of cysteine protease activity. While the biologically active hCC wt is a monomeric protein, all crystallization efforts to date have resulted in a three-dimensional domain-swapped dimeric structure. In the recently published structure of a mutated hCC, the monomeric fold was preserved by a stabilization of the conformationally constrained loop L1 caused by a single amino-acid substitution: Val57Asn. Additional hCC mutants were obtained in order to elucidate the relationship between the stability of the L1 loop and the propensity of human cystatin C to dimerize. In one mutant Val57 was substituted by an aspartic acid residue, which is favoured in β-turns, and in the second mutant proline, a residue known for broadening turns, was substituted for the same Val57. Here, 2.26 and 3.0Å resolution crystal structures of the V57D andV57P mutants of hCC are reported and their dimeric architecture is discussed in terms of the stabilization and destabilization effects of the introduced mutations.

Original languageEnglish (US)
Pages (from-to)577-586
Number of pages10
JournalActa Crystallographica Section D: Biological Crystallography
Volume69
Issue number4
DOIs
StatePublished - Apr 2013

Keywords

  • amyloid
  • cysteine protease inhibitors
  • human cystatin C
  • single-point mutations

ASJC Scopus subject areas

  • Structural Biology

Fingerprint Dive into the research topics of 'Structural characterization of V57D and V57P mutants of human cystatin C, an amyloidogenic protein'. Together they form a unique fingerprint.

  • Cite this