Light Regulation of Enzyme Allostery through Photo-responsive Unnatural Amino Acids

Andrea C. Kneuttinger, Kristina Straub, Philipp Bittner, Nadja A. Simeth, Astrid Bruckmann, Florian Busch, Chitra Rajendran, Enrico Hupfeld, Vicki H. Wysocki, Dominik Horinek, Burkhard Koenig, Rainer Merkl, Reinhard Sterner*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Scopus)

Abstract

Imidazole glycerol phosphate synthase (ImGPS) is an allosteric bienzyme complex in which substrate binding to the synthase subunit HisF stimulates the glutaminase subunit HisH. To control this stimulation with light, we have incorporated the photo-responsive unnatural amino acids phenylalanine-4'-azobenzene (AzoF), o-nitropiperonyl-O-tyrosine (NPY), and methyl-o-nitropiperonyllysine (mNPK) at strategic positions of HisF. The light-mediated isomerization of AzoF at position 55 (fS55AzoF(E) fS55AzoF(Z)) resulted in a reversible 10-fold regulation of HisH activity. The light-mediated decaging of NPY at position 39 (fY39NPY -> fY39) and of mNPK at position 99 (fK99mNPK -> fK99) led to a 4- to 6-fold increase of HisH activity. Molecular dynamics simulations explained how the unnatural amino acids interfere with the allosteric machinery of ImGPS and revealed additional aspects of HisH stimulation in wild-type ImGPS. Our findings show that unnatural amino acids can be used as a powerful tool for the spatio-temporal control of a central metabolic enzyme complex by light.

Original languageEnglish
Pages (from-to)1501-1514.e9
Number of pages23
JournalCell Chemical Biology
Volume26
Issue number11
DOIs
Publication statusPublished - 21-Nov-2019

Keywords

  • GLYCEROL PHOSPHATE SYNTHASE
  • OPTICAL CONTROL
  • GLUTAMINE AMIDOTRANSFERASE
  • STRUCTURE VALIDATION
  • MOLECULAR-DYNAMICS
  • PROTECTING GROUPS
  • PROTEIN FUNCTION
  • BIOCATALYSIS
  • ACTIVATION
  • REDUCTION

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