The unfolding pathways of the native and molten globule states of 5-aminolevulinate synthase

Research output: Contribution to journalArticle

Authors

External Institution(s)

  • University of South Florida
  • Saint Louis University

Details

Original languageEnglish (US)
Pages (from-to)321-327
Number of pages7
JournalBiochemical and Biophysical Research Communications
Volume480
Issue number3
StatusPublished - Nov 18 2016
Peer-reviewedYes

Abstract

In this communication, we report the equilibrium and kinetic properties of the unfolding pathways of the native (pH 7.5) and alkaline molten globule (pH 10.5) states of the pyridoxal 5′-phosphate (PLP)-dependent enzyme 5-aminolevulinate synthase (ALAS). The stability of the molten globule state is adversely affected by thermal- and guanidine hydrochloride (GuHCl)-induced denaturation, and the equilibrium unfolding pathways, irrespective of pH, cannot be described with simple two-state models. Rapid kinetic measurements, in the presence of denaturing GuHCl concentrations, reveal that at pH 10.5, the rate of ALAS denaturation is 3 times faster than at pH 7.5. From pH jump experiments, comparable rates for the denaturation of the tertiary structure and PLP-microenvironment were discerned, indicating that the catalytic active site geometry strongly depends on the stable tertiary structural organization. Lastly, we demonstrate that partially folded ALAS tends to self-associate into higher oligomeric species at moderate GuHCl concentrations.

    Research areas

  • 5-Aminolevulinate synthase, Heme, Molten globule, Protein unfolding, Pyridoxal phosphate

Citation formats

APA

Stojanovski, B. M., Breydo, L., Uversky, V. N., & Ferreira, G. C. (2016). The unfolding pathways of the native and molten globule states of 5-aminolevulinate synthase. Biochemical and Biophysical Research Communications, 480(3), 321-327. https://doi.org/10.1016/j.bbrc.2016.10.037

Harvard

Stojanovski, BM, Breydo, L, Uversky, VN & Ferreira, GC 2016, 'The unfolding pathways of the native and molten globule states of 5-aminolevulinate synthase', Biochemical and Biophysical Research Communications, vol. 480, no. 3, pp. 321-327. https://doi.org/10.1016/j.bbrc.2016.10.037