@article{NitschkeWangSchmiederetal.2013,
  author    = {Nitschke, Felix and Wang, Peixiang and Schmieder, Peter and Girard, Jean-Marie and Awrey, Donald E. and Wang, Tony and Israelian, Johan and Zhao, XiaoChu and Turnbull, Julie and Heydenreich, Matthias and Kleinpeter, Erich and Steup, Martin and Minassian, Berge A.},
  title     = {Hyperphosphorylation of glucosyl C6 carbons and altered structure of glycogen in the neurodegenerative epilepsy lafora disease},
  series = {Cell metabolism},
  volume    = {17},
  journal   = {Cell metabolism},
  number    = {5},
  publisher = {Cell Press},
  address   = {Cambridge},
  issn      = {1550-4131},
  doi       = {10.1016/j.cmet.2013.04.006},
  pages     = {756 -- 767},
  year      = {2013},
  abstract  = {Laforin or malin deficiency causes Lafora disease, characterized by altered glycogen metabolism and teenage-onset neurodegeneration with intractable and invariably fatal epilepsy. Plant starches possess small amounts of metabolically essential monophosphate esters. Glycogen contains similar phosphate amounts, which are thought to originate from a glycogen synthase error side reaction and therefore lack any specific function. Glycogen is also believed to lack monophosphates at glucosyl carbon C6, an essential phosphorylation site in plant starch metabolism. We now show that glycogen phosphorylation is not due to a glycogen synthase side reaction, that C6 is a major glycogen phosphorylation site, and that C6 monophosphates predominate near centers of glycogen molecules and positively correlate with glycogen chain lengths. Laforin or malin deficiency causes C6 hyperphosphorylation, which results in malformed long-chained glycogen that accumulates in many tissues, causing neurodegeneration in brain. Our work advances the understanding of Lafora disease pathogenesis and suggests that glycogen phosphorylation has important metabolic function.},
  language  = {en}
}
@article{SchmiederNitschkeSteupetal.2013,
  author    = {Schmieder, Peter and Nitschke, Felix and Steup, Martin and Mallow, Keven and Specker, Edgar},
  title     = {Determination of glucan phosphorylation using heteronuclear H-1,C-13 double and H-1,C-13,P-31 triple-resonance NMR spectra},
  series = {Magnetic resonance in chemistry},
  volume    = {51},
  journal   = {Magnetic resonance in chemistry},
  number    = {10},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0749-1581},
  doi       = {10.1002/mrc.3996},
  pages     = {655 -- 661},
  year      = {2013},
  abstract  = {Phosphorylation and dephosphorylation of starch and glycogen are important for their physicochemical properties and also their physiological functions. It is therefore desirable to reliably determine the phosphorylation sites. Heteronuclear multidimensional NMR-spectroscopy is in principle a straightforward analytical approach even for complex carbohydrate molecules. With heterogeneous samples from natural sources, however, the task becomes more difficult because a full assignment of the resonances of the carbohydrates is impossible to obtain. Here, we show that the combination of heteronuclear H-1,C-13 and H-1,C-13,P-31 techniques and information derived from spectra of a set of reference compounds can lead to an unambiguous determination of the phosphorylation sites even in heterogeneous samples.},
  language  = {en}
}