1 / 22

Protein aggregation via 3D domain swapping Mariusz Jask o lski

Protein aggregation via 3D domain swapping Mariusz Jask o lski Dept. of Crystallography, A.Mickiewicz Univ. Center for Biocrystallographic Research Poznan , Poland. 3D domain swapping (D.Eisenberg). a protein domain breaks its contact with other domains;

thane-sykes
Download Presentation

Protein aggregation via 3D domain swapping Mariusz Jask o lski

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Protein aggregation via 3D domain swapping Mariusz Jaskolski Dept. of Crystallography, A.Mickiewicz Univ. Center for Biocrystallographic Research Poznan, Poland

  2. 3D domain swapping (D.Eisenberg)... a protein domain breaks its contact with other domains; its place is taken by the same domain of another protein; interlaced dimer or higher oligomer is formed • swapped domain: 2-ry str. element or globular domain • closed monomer: conformation before transition • open monomer: conformation after transition • hinge loop: links the swapped domain to the rest • closed interface: preserved in the oligomer • open interface: new, absent in the monomer

  3. 3D domain swapping examples • diphteria toxin • RNase (A, BS) • CksHs (cell cycle regulation) • CD2 • staphylococcal nuclease • cro (DNA represor) • spectrin (cytoskeleton) • antibody fragments • human prion protein • human cystatin C • crystallins • growth factors/cytokines • feromon transport/odorant binding • SH3 (signal transduction) bona fide quasi     

  4. Human cystatin C (HCC) • small protein (120 aa) • abundant in body fluids • high concentration in cerebrospinal fluid • potent inhibitor of cysteine proteases (monomer) • N-term. and 2 -hairpins bind the enzyme • degradation  N-truncated variant • two S-S bridges in C-terminal part • structure of N-truncated chicken analog known • endemic L68Q mutant causes HCCAA

  5. Amyloidogenicproperties ofHCC • L68Q mutantmore stableas dimer • dimeric L68Q mutant found in blood of HCCAA patients • L68Q mutant forms mssive amyloid deposits • massive brain hemorrhages and early death in HCCAA • fevers accelerate progress of HCCAA • N-truncated protein (THCC) found in amyloid deposits • normal variant (L68) also participates in fibril formation • elevated temp. or lower pH lead to oligomerization in vitro

  6. HCC – speculative thermodynamics hydrophilic patch on exposed surface Energy partial unfolding Monomer thermal energy L68Q destabilization Monomer open interface Dimer Dimer WT L68Q L68Q HCC dimers are observed in blood plasma of HCCAA patients

  7. Even with one exchangeble domain open-ended 3D domain swapping may lead to infinite polymerization

  8. Incubation at pH 37° C +0.5 M Gnd.HCl, pH 7.4 L68Q HCC HCC

  9. L68Q HCC HCC stab1 and stab2 of L68Q / HCC

  10. Conclusions • Full-length and N-truncated HCC are both capable of dimerization via 3D domain swapping • The dimer open interface in the hinge region is flexible • S-S bridges preventing domain swapping inhibit dimerization

  11. Collaboration Robert Janowski A.Mickiewicz Univ. Poznan Maciej Kozak Magnus Abrahamson Lund Univ. Anders Grubb Maria Nilsson Xin Wang Zbigniew Grzonka Univ. of Gdansk

More Related