Aggregation of A beta Alzheimer's disease-related peptide studied by dynamic light scattering.

The aggregation behavior of the major component of Alzheimer's disease-related, amyloid peptides, Abeta-(1-40) and Abeta-(1-42), was studied in solution using dynamic light scattering. With most solvents employed, we found fibrils coexisting with oligomeric Abeta species. Pronounced differences were observed in aggregation of Abeta-(1-40) and (1-42) sequences in acetonitrile-water mixtures.

[Synthesis of peptides with gastrinlike activity. Studies on the structure-activity relationship of the natural hormone human little gastrin I].

To identify the role of the block of glutamic acid residues characteristic for the gastrin molecule, a series of shortened peptides related to the human little-gastrin-I sequence were synthesized. The biological activities of these gastrin peptides strongly suggest in the pentaglutamic acid sequence a specific information for a pronounced amplification of the hormonal activity.