1Y4C

Designed Helical Protein fusion MBP

Summary for 1Y4C

• Entry DOI: 10.2210/pdb1y4c/pdb
• Related: 4HB1
• Related PRD ID: PRD_900001
• Descriptor: Maltose binding protein fused with designed helical protein, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose (3 entities in total)
• Functional Keywords: de novo designed helical protein, maltose binding protein fusion, de novo protein
• Biological source: Escherichia coli
• Cellular location: Periplasm: P02928
• Total number of polymer chains: 1
• Total formula weight: 54631.48

Authors

LaPorte, S.L.,Forsyth, C.M.,Cunningham, B.C.,Miercke, L.J.,Akhavan, D.,Stroud, R.M. (deposition date: 2004-11-30, release date: 2005-02-15, Last modification date: 2024-02-14)

Primary citation

LaPorte, S.L.,Forsyth, C.M.,Cunningham, B.C.,Miercke, L.J.,Akhavan, D.,Stroud, R.M.
De novo design of an IL-4 antagonist and its structure at 1.9 A.
Proc.Natl.Acad.Sci.Usa, 102:1889-1894, 2005

PubMed Abstract: An IL-4 antagonist was designed based on structural and biochemical analysis of unbound IL-4 and IL-4 in complex with its high-affinity receptor (IL-4Ralpha). Our design strategy sought to capture a protein-protein interaction targeting the high affinity that IL-4 has for IL-4Ralpha. This strategy has impact due to the potential relevance of IL-4Ralpha as a drug target in the treatment of asthma. To mimic the IL-4 binding surface, critical side chains for receptor binding were identified, and these side chains were transplanted onto a previously characterized, de novo-designed four-helix protein called designed helical protein 1 (DHP-1). This first-generation design resolved the ambiguity previously described for the connectivity between helices in DHP-1 and resulted in a protein capable of binding to IL-4Ralpha. The second-generation antagonist was based upon further molecular modeling, and it succeeded in binding IL-4Ralpha better than the first-generation. This protein, termed DHP-14-AB, yielded a protein with a cooperative unfolding transition (DeltaGu0=8.1 kcal/mol) and an IC50 of 27 microM when in competition with IL-4 whereas DHP-1 had no affinity for IL-4Ralpha. The crystal structure of DHP-14-AB was determined to 1.9-A resolution and was compared with IL-4. This comparison revealed how design strategies targeting protein-protein interactions require high-resolution 3D data and the incorporation of orientation-specific information at the level of side-chains and secondary structure element interactions.

PubMed: 15684085
DOI: 10.1073/pnas.0408890102

Experimental method

X-RAY DIFFRACTION (1.9 Å)