Background

Pathologies such as Alzheimer's, Parkinson's and cataract are associated with formation and accumulation of protein aggregates that play an important role in disease development. It is also well established that these diseases are linked to formation of oxidative protein modifications including covalent non-reducible protein cross-links, such as dityrosine. It is however not known whether such cross-links are a consequence or cause of protein aggregation. There is therefore an urgent need to improve our fundamental understanding of the biochemical mechanisms of protein aggregation and crosslinking.

As a model system to study protein aggregation, we employ Anastellin, a fragment of the first type III domain which mimics a partially unfolded intermediate implicated in the assembly of fibronectin fibrils. Anastellin also inhibits cell proliferation, has anti-angiogenic properties, and suppresses tumor growth and metastasis. Anastellin contains several aromatic residues which are potential targets of inflammatory oxidants such as peroxynitrous acid or those generated by the leukocyte-derived heme enzyme myeloperoxidase, such as hypochlorous acid. These oxidants induce aggregation and formation of crosslinks in Anastellin. Such structural perturbation is likely to impact on the ability of Anastellin to induce fibrillation of fibronectin.

Hypothesis and aim

The hypothesis of this project is that inflammatory oxidants will induce cross-links in Anastellin that impact on the ability of this protein to induce formation of protein fibrils and aggregates. The overall aim is to determine the extent and nature of cross-links in aggregated and monomeric species of Anastellin exposed to oxidants. This data will provide important information regarding mechanisms of protein aggregation related to disease development. A range of state-of-the-art bioanalytical techniques will be applied including mass spectrometry, chromatography, spectrophotometry and electrophoresis.

Contact Associate Professor Per Hägglund for more information on the project.