Title:Assessment of the Effect of Macromolecular Crowding on Aggregation Behaviour of a Model Amyloidogenic Peptide
Volume: 22
Issue: 1
Author(s): Bharti Gaharwar, Shalini Gour, Vibha Kaushik, Nimisha Gupta, Vijay Kumar, Gerd Hause and Jay Kant Yadav
Affiliation:
Keywords:
Amyloid, light scattering, macromolecular crowding, protein aggregation, thioflavin T binding.
Abstract: Accumulation of ordered protein aggregates (or amyloids) represents a hallmark of many diseases
(e.g., Alzheimer’s disease, type II diabetes, Parkinson’s diseases etc.), results from intermolecular association
of partially unfolded proteins/ peptides. Such associations usually take place in highly crowded conditions.
The aggregates, which are formed under in vitro and in vivo conditions exhibit substantial variations in
their structure and function. Such heterogeneities in amyloids might arise due to macromolecular crowding
that is usually omitted under in vitro conditions. The current study is an attempt to assess the effects of macromolecular
crowding on amyloid formation using a model amyloidogenic peptide. The sequence of the peptide
was derived from C-terminal region (RATQIPSYKKLIMY) of PAP(248-286), which naturally occurs in
human semen as amyloid aggregates and is known for boosting HIV infectivity. This model peptide forms sedimentable
and fibrillar aggregates in aqueous buffer and shows the characteristic features of amyloids. In the presence of macromolecular
crowders the morphological features of the amyloids are significantly altered and resulted in the formation of
shorter amyloid aggregates. The current study assumes the hypothesis that macromolecular crowding in the biological system
favours formation of heterogeneous classes of aggregates and each of them might differ in their biophysical and biological
properties.
