NMR-detected order in core residues of denatured bovine pancreatic trypsin inhibitor

E. Barbar, M. Hare, M. Makokha, G. Barany, C. Woodward

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


The NMR characteristics of [14-38]Abu, a synthetic variant of BPTI that is partially folded in aqueous buffer near neutral pH, support a model of early folding events which begin with stabilization of the nativelike, slow exchange core [Barbar, E., Hare, M., Daragan, V., Barany, G., and Woodward, C. (1998) Biochemistry 37, 7822-7833 (1)]. In partially folded [14-38]Abu, urea denaturation profiles for representative amide protons show that global unfolding is non-two-state and that core residues require a higher concentration of urea to unfold. Dynamic properties of pH-denatured [14-38]Abu and fully reduced and unfolded BPTI analogue were determined from heteronuclear NMR relaxation measurements at similar solution conditions. Differences at various sites in the polypeptide chain were evaluated from spectral density functions determined from T1, T2, and steady-state heteronuclear NOE data. Although denatured [14 - 38]Abu contains no persistent secondary structure, its most ordered residues are those that, in native BPTI, fold into the slow exchange core. The fully reduced analogue is significantly more mobile and shows less heterogeneous dynamics, but at 1 °C, restricted motion is observed for residues in the central segments of the polypeptide chain. These observations indicate that there is a developing core or cores even in highly unfolded species. Apparently the effect of 14-38 disulfide on unfolded BPTI is to preferentially order and stabilize residues in the core.

Original languageEnglish (US)
Pages (from-to)9734-9742
Number of pages9
Issue number32
StatePublished - Aug 14 2001


Dive into the research topics of 'NMR-detected order in core residues of denatured bovine pancreatic trypsin inhibitor'. Together they form a unique fingerprint.

Cite this