(continued from our coverage of the earlier session)
Glabe’s group (including several other PIs joined by a LLHF network grant) has been developing anti-amyloid antibodies, some of which are conformation-specific but not necessarily sequence-specific; in other words, antibodies that recognize common features of amyloid aggregates formed by many different types of protein (e.g., Aß but also alpha-synuclein, IAPP, and other peptides involved in aggregation-based diseases). These reagents will be useful in research but also potentially as therapies against multiple age-related illnesses.
Since last year, the group has been attempting to determine the structure of amyloid oligomers. Problem: amyloids don’t crystallize, so the current strategy is to form co-crystals between anti-amyloid antibodies and prefibrillar oligomers — or, failing that, crystallize the antibody alone and make inferences about the amyloid structure (which should be the ‘negative space’ of the antibody Fab fragment — assuming, of course, that the antibody doesn’t have to undergo a dramatic structural rearrangement in order to bind). Another member of the collaboration has been trying to understand the folded and unfolded states of amyloidogenic proteins, using solution-based techniques (EPR, NMR) rather than crystallography.
Another new direction in this project: studying the effect of amyloid oligomers on membrane conductance. Amyloid oligomers, which are toxic to cells, have a significant effect on the electrical properties of lipid bilayers: specifically, they increase the rate of depolarization. Novel, and this will be especially relevant to the emerging idea that AD is a disease of neuronal connectivity (i.e., interfering with membrane conductance) as well as cell toxicity.
Not a whole lot of new stuff on the therapeutic angle this time around, but you can’t win the lottery every year.