15N NMR studies of the conformation of E. coli dihydrofolate reductase in complex with folate or methotrexate

Fu Yung Huang, Qing Xian Yang, Tai huang Huang

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We have employed 15N NMR to characterize the conformations of Escherichia coli dihydrofolate reductase (ECDHFR) in complex with [5-15N]folate or [5-15N]methotrexate (MTX). Two 15N resonances were observed for DHFR/MTX binary complex. The relative population of these two conformations is pH dependent. Addition of NADP+ or NADPH results in the disappearance of the low field resonance. In contrast, only one conformation was observed for both the DHFR/folate and DHFR/folate/NADP+ complexes. However, the 15N chemical shift of [5-15N]folate in the binary DHFR/folate complex is 7.28 ppm upfield from that of the ternary complex, suggesting the possible loss of a hydrogen bonding to N5 of folate in the ternary complex.

Original languageEnglish
Pages (from-to)231-234
Number of pages4
JournalFEBS Letters
Issue number2
Publication statusPublished - 1991 Sep 9



  • Dihydrofolate reductase
  • Folate
  • Methotrexate
  • NADP
  • NMR

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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