Crowding interactions perturb structure and stability by destabilizing the stable core of the α-subunit of tryptophan synthase.
The consequences of crowding derived from relatively small and intrinsically disordered proteins are not clear yet. We report the effect of ficoll-70 on the structure and stability of native and partially folded states of the 29 kDa alpha subunit of tryptophan synthase (αTS). Overall, combining the changes in the circular dichroism and fluorescence spectra, in conjunction with the gradual loss of cooperativity under urea denaturation in the presence of increasing amounts of ficoll, it may be concluded that the crowding agent perturbs not only the native state but also the partially folded state of αTS. Importantly, NMR data indicate that ficoll interacts with the residues that constitute the stable core of the protein thus shedding light on the origin of the observed perturbation.
Department of Biological Sciences, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, India.
Rajashekar Varma
RV
Kadumuri
Department of Biological Sciences, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, India.
Jagadeesh
J
Gullipalli
Department of Biological Sciences, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, India.
SriVidya
S
Subramanian
NMR Research Centre, Indian Institute of Science, Bangalore, India.
Garima
G
Jaipuria
NMR Research Centre, Indian Institute of Science, Bangalore, India.
Hanudatta S
HS
Atreya
Department of Biological Sciences, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, India.
Ramakrishna
R
Vadrevu
D004795:Enzyme Stability; D005362:Ficoll / Q000737:chemistry; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular; D011489:Protein Denaturation; D000072417:Protein Domains; D014367:Tryptophan Synthase / Q000737:chemistry*; D014508:Urea / Q000737:chemistry
D005362:Ficoll; D014508:Urea; D014367:Tryptophan Synthase
NMR; crowding; ficoll; structure/stability modulation; α-subunit of tryptophan synthase