Abstract
Purpose :
Exfoliation glaucoma (XFG) is a common form of secondary glaucoma caused by progressive accumulation of insoluble elastic fiber-based microfibrillar deposits in the eye. XFG is the ocular manifestation of the age-related systemic disorder known as pseudoexfoliative syndrome (PEX); fibrillar deposits are found in various organs of PEX patients including the skin, heart, lungs, and brain. The disease is highly prevalent in the elderly in certain ethnic groups, suggesting the role of genetic and environmental factors. Its exact pathogenesis is not known, however, multiple single nucleotide polymorphisms in the lysyl oxidase-like 1 (LOXL-1) gene have been identified to correlate with PEX. LOXL-1 belongs to the family of amine oxidases responsible for the maintenance and crosslinking of elastin and collagen fibers. LOXL-1 is a component of pseudoexfoliative material and its expression is upregulated in the early stages of the disease, therefore, targeting LOXL-1 may be a viable strategy to treat XFG.
Methods :
In order to develop assays that could serve as tools for the diagnosis of XFG from human samples based on LOXL-1 activity and to evaluate the enzyme as a potential drug target, we expressed and purified human LOXL-1 from E. coli constructs. Enzyme activity was measured using colorimetry, fluorimetry, and luminometry, leveraging the enzyme’s ability to generate aldehydes and hydrogen peroxide. Small molecules were screened using differential scanning fluorimetry for possible interaction with LOXL-1.
Results :
A chemiluminescence-based assay method was developed that can be used to quantify lysyl oxidase activity in biological samples. Using differential scanning fluorimetry, we identified small molecules that affect the stability of LOXL-1 and screened these for enzyme inhibition.
Conclusions :
Our results highlight LOXL-1 as a potential target for identifying and treating XFG.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.