Branched KLVFF tetramers strongly potentiate inhibition of beta-amyloid aggregation

The key pathogenic event in the onset of Alzheimer's disease (AD) is the aggregation of -amyloid (A) peptides into toxic aggregates. Molecules that interfere with this process might act as therapeutic agents for the treatment of AD. The amino acid residues 16-20 (KLVFF) are known to be essential for the aggregation of A. In this study, we have used a first-generation dendrimer as a scaffold for the multivalent display of the KLVFF peptide. The effect of four KLVFF peptides attached to the dendrimer (K4) on A aggregation was compared to the effect of monomeric KLVFF (K1). Our data show that K4 very effectively inhibits the aggregation of low-molecular-weight and protofibrillar A1-42 into fibrils, in a concentration-dependent manner, and much more potently than K1. Moreover, we show that K4 can lead to the disassembly of existing aggregates. Our data lead us to propose that conjugates that bear multiple copies of KLVFF might be useful as therapeutic agents for the treatment of Alzheimer's disease

Multivalent peptide and protein dendrimers using native chemical ligation

A wide variety of well-defined multivalent peptides and proteins can be made by conjugating synthetic peptides and recombinantly expressed proteins to cysteine-functionalized dendrimers using native chemical ligation (see picture). This modular approach provides access to dendrimers that are attractive both for understanding fundamental issues of multivalency in biological interactions as well as for biomedical applications