Deciphering the anti-Parkinson’s activity of sulfated polysaccharides from Chlamydomonas reindertaii on the a-synuclein mutants A30P, A53T, E46K, E57K and E35K

Parkinsonism-linked mutations in alanine and glutamic acid residues of the pre-synaptic protein alpha-Synuclein (alpha-Syn) affect specific tertiary interactions essential for stability of the native state and make it prone to more aggregation. Many of the currently available drugs used for the treatment of Parkinson's disease (PD) are not very effective and are associated with multiple side effects. Recently, marine algae have been reported to have sulphated polysaccharides which offers multiple pharmaceutical properties. With this background, we have isolated sulphated polysaccharides from Chlamydomonas reinhardtii (Cr-SPs) and investigated their effects on inhibition of fibrillation/aggregation of alpha-Syn mutants through a combination of spectroscopic and microscopic techniques. The kinetics of alpha-Syn fibrillation establishes that Cr-SPs are very effective in inhibiting fibrillation of alpha-Syn mutants. The morphological changes associated with the fibrillation/aggregation process have been monitored by transmission electron microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis gel image suggests that Cr-SPs increase the amount of soluble protein after completion of the fibrillation/aggregation process. The circular dichroism results showed that Cr-SPs efficiently delay the conversion of native protein into beta-sheet-rich structures. Thus, the current work has considerable therapeutic implications towards deciphering the potential of Cr-SPs to act against PD and other protein aggregation-related disorders.