Designed protein tetramer zipped together with a hydrophobic Alzheimer homology: A structural clue to amyloid assembly

TY - JOUR

T1 - Designed protein tetramer zipped together with a hydrophobic Alzheimer homology

T2 - A structural clue to amyloid assembly

AU - Otzen, Daniel E.

AU - Kristensen, Ole

AU - Oliveberg, Mikael

PY - 2000/8/29

Y1 - 2000/8/29

N2 - Limited solubility and precipitation of amyloidogenic sequences such as the Alzheimer peptide (β-AP) are major obstacles to a molecular understanding of protein fibrillation and deposition processes. Here we have circumvented the solubility problem by stepwise engineering a β-AP homology into a soluble scaffold, the monomeric protein S6. The S6 construct with the highest β-AP homology crystallizes as a tetramer that is linked by the β-AP residues forming intermolecular antiparallel β-sheets. This construct also shows increased coil aggregation during refolding, and a 14-mer peptide encompassing the engineered sequence forms fibrils. Mutational analysis shows that intermolecular association is linked to the overall hydrophobicity of the sticky sequence and implies the existence of 'structural gatekeepers' in the wild-type protein, that is, charged side chains that prevent aggregation by interrupting contiguous stretches of hydrophobic residues in the primary sequence.

AB - Limited solubility and precipitation of amyloidogenic sequences such as the Alzheimer peptide (β-AP) are major obstacles to a molecular understanding of protein fibrillation and deposition processes. Here we have circumvented the solubility problem by stepwise engineering a β-AP homology into a soluble scaffold, the monomeric protein S6. The S6 construct with the highest β-AP homology crystallizes as a tetramer that is linked by the β-AP residues forming intermolecular antiparallel β-sheets. This construct also shows increased coil aggregation during refolding, and a 14-mer peptide encompassing the engineered sequence forms fibrils. Mutational analysis shows that intermolecular association is linked to the overall hydrophobicity of the sticky sequence and implies the existence of 'structural gatekeepers' in the wild-type protein, that is, charged side chains that prevent aggregation by interrupting contiguous stretches of hydrophobic residues in the primary sequence.

UR - http://www.scopus.com/inward/record.url?scp=0034730203&partnerID=8YFLogxK

U2 - 10.1073/pnas.160086297

DO - 10.1073/pnas.160086297

M3 - Journal article

C2 - 10944185

AN - SCOPUS:0034730203

SN - 0027-8424

VL - 97

SP - 9907

EP - 9912

JO - Proceedings of the National Academy of Sciences (PNAS)

JF - Proceedings of the National Academy of Sciences (PNAS)

IS - 18

ER -