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“Personalized mechanisms of Lafora disease using Differential Scanning Fluorimetry”
Author(s) -
Donohue Kit,
Brewer M. Katherine,
Vander Kooi Craig W,
Gentry Matthew S
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.636.4
Subject(s) - lafora disease , glycogen , glycogen synthase , biology , biochemistry , phosphorylation , computational biology , phosphatase
Lafora disease is an autosomal recessive neurodegenerative disease. Patients grow up normally for their first decade of life, then develop severe epilepsy, and die in their 20s or 30s from massive neurodegeneration. The field has demonstrated that the pathogenic agent of the disease are aberrant glycogen molecules. Glycogen phosphorylation impacts the branch point and chain length distribution within the glycogen molecule, determining both the granule shape and its accessibility to regulating enzymes. Laforin is the only known mammalian phosphatase capable of modifying the phosphorylation status of glycogen. When laforin is mutated, aberrant glycogen forms inclusion bodies and drives Lafora disease progression. Therefore, it is important to understand how different mutations in laforin affect its ability to bind and dephosphorylate glycogen. However, defining protein‐carbohydrate interactions can be challenging because many binding techniques cannot accurately measure low binding affinities. We utilized differential scanning calorimetry (DSC) in combination with differential scanning fluorimetry (DSF) and a unique algorithm to consistently predict a true K d using DSF data. Through the use of short polysaccharides that approximate glycogen micro‐structures, we show that the DSF method can be used in a high‐throughput assay to assess laforin‐carbohydrate interactions. With this data, we compare how different mutations impact the binding affinity of laforin to glycogen and how changes to glycogen structure alter the ability of laforin to bind and dephosphorylate glycogen. These results provide unique insights into personalized mechanisms of Lafora disease. Support or Funding Information This work was supported by the National Science Foundation through NSF MCB1817417 and NSF OIA 1355438 This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .