Starch, metabolism and structure

Starch is by far the most important molecular principle for providing energy storage for plants and in turn for human and animal energy intake. The impact of starch stems from its hyper-efficient deposition of glucose in semicrystalline granules combined with its high ability to be made bioavailable in the plant despite the high density and crystallinity that normally prevents hydrolytic enzymes to efficiently attack the granule. Our carbohydrate model explains the structural basis for how rare phosphate esters present in starch granules can stimulate its degradation in the cell. Glucan water dikinases track and tag crystalline sites and then execute 3-phosphorylation of few glucose residues generating kinks in the regular helical glucosidic bond structure creating local disorder. This finding adds new perspective on how organisms increase bioavailability of a carbohydrate matrix by inducing amorphisation by a phosphate-induced tracker – executor mechanism.

Selected publications

  • Goldstein A, Annor G, Putaux JL, Hebelstrup KH, Blennow A, Bertoft E (2016) Impact of full range of amylose contents on the architecture of starch granules. International Journal of Biological Macromolecules, 89, 305–318
  • Shaik, SS, Obata, T, Hebelstrup, KH, Fernie, AR, Mateiu, RV, Blennow, A. (2016) Alterations in starch branching enzyme and glucan water dikinase: Effects on grain physiology and metabolism. PLoS ONE 11(2): e0149613. doi:10.1371/journal.pone.0149613 (2016)
  • Shaik, S.S., Carciofi, M., Martens, H.J., Hebelstrup, K.H., and Blennow, A. (2014) Starch bioengineering affects cereal grain germination and seedling establishment. J. Exp. Bot. 65/9, 2257–2270. DOI 10.1093/jxb/eru107
  • Tanackovic, V., Svensson, J.T., Jensen, S.L., Buléon, A and Blennow A. (2014) The deposition and characterization of starch in Brachypodium distachyon. J. Exp. Bot. 65(18) 5179-5192
  • Blennow, A. and Engelsen, S.B. (2010) Helix-breaking news: fighting crystalline starch energy deposits in the cell. Trends Plant Sci. 15/4, 236-240  doi:10.1016/j.tplants.2010.01.009
  • Damager, I., Engelsen, S.B., Blennow, A., Møller, B.L., and Motawia, S.M. (2010) First principles insight into starch-likea-glucans: their synthesis, conformation and hydration. Chem. Rev. 110, 2049-80