Redesigning specificity in miniproteins

This work focuses on designing specific miniprotein interactions using computational models and then testing these designs with experiments. Miniproteins are small, autonomously-folding proteins that are excellent for testing protein designs because they can be chemically synthesized and computationally modeled. Despite their diminutive size, miniproteins are used as minimal models to discern important features, such as folding and interaction specificity, in natural proteins. A 21-residue [beta][beta][alpha] homotetramer miniprotein (BBA) was computationally redesigned to interact as a heterotetramer. Protein design calculations revealed a large/small pattern of hydrophobic residues in the core and charge complementarity on the surface as a mechanism for attaining heterospecificity. Solution studies showed the designed protein is a tetramer and interacts in the same stoichiometry as its parent homotetramer. The x-ray crystal structure of the heterotetramer revealed a structure very close to the designed structure with near-perfect prediction of core side-chain packing. In a second round of design, the BBA heterotetramer was stabilized to near-native stability. Next, the coiled-coil region within the Bcr (breakpoint cluster region) oligomerization domain was used to probe antiparallel versus parallel helix-orientation specificity in coiled coils.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Biology.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Taylor, Christina Marie

Advisor dc:contributor.advisor

• Amy E. Keating.

• Biology.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/34192
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/34192

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34192