Analysis of β-C-terminal salt bridges in T-state hemoglobin by trapping tertiary conformations in silica gels.

ABSTRACT: Encapsulation of a protein in wet silica gels greatly slows its large-scale motions, allowing the characterization of defined protein conformations during functional and spectroscopic measurements. This technique has revealed the coexistence of two or more functionally distinct tertiary conformations in T-state human hemoglobin, but their structural basis remains unclear. Here, we extend this approach to analyze the β-C-terminal salt bridges in the T-state hemoglobin populations. To this end, we first compare three representative sol-gel trapping protocols by transient absorption characterization of both directions of the hemoglobin allosteric transition (R-to-T and T-to-R) and by O₂ equilibrium measurements. Results reveal protocol-dependent variations in slow-down factor for t

SUBMITTER: Shibayama N 

PROVIDER: S-EPMC12168133 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature