Dataset Information

Neutron structure of human carbonic anhydrase II: a hydrogen-bonded water network "switch" is observed between pH 7.8 and 10.0.

ABSTRACT: The neutron structure of wild-type human carbonic anhydrase II at pH 7.8 has been determined to 2.0 Å resolution. Detailed analysis and comparison to the previously determined structure at pH 10.0 show important differences in the protonation of key catalytic residues in the active site as well as a rearrangement of the H-bonded water network. For the first time, a completed H-bonded network stretching from the Zn-bound solvent to the proton shuttling residue, His64, has been directly observed.

SUBMITTER: Fisher Z

PROVIDER: S-EPMC3371383 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Neutron structure of human carbonic anhydrase II: a hydrogen-bonded water network "switch" is observed between pH 7.8 and 10.0.

Fisher Zoë Z Kovalevsky Andrey Y AY Mustyakimov Marat M Silverman David N DN McKenna Robert R Langan Paul P

Biochemistry 20111012 44

The neutron structure of wild-type human carbonic anhydrase II at pH 7.8 has been determined to 2.0 Å resolution. Detailed analysis and comparison to the previously determined structure at pH 10.0 show important differences in the protonation of key catalytic residues in the active site as well as a rearrangement of the H-bonded water network. For the first time, a completed H-bonded network stretching from the Zn-bound solvent to the proton shuttling residue, His64, has been directly observed. ...[more]

PMID: 21988105

Similar Datasets

Project description:Silk is a protein of interest to both biological and industrial sciences. The silkworm, Bombyx mori, forms this protein into strong threads starting from soluble silk proteins using a number of biochemical and physical cues to allow the transition from liquid to fibrous silk. A pH gradient has been measured along the gland, but the methodology employed was not able to precisely determine the pH at specific regions of interest in the silk gland. Furthermore, the physiological mechanisms responsible for the generation of this pH gradient are unknown. In this study, concentric ion selective microelectrodes were used to determine the luminal pH of B. mori silk glands. A gradient from pH 8.2 to 7.2 was measured in the posterior silk gland, with a pH 7 throughout the middle silk gland, and a gradient from pH 6.8 to 6.2 in the beginning of the anterior silk gland where silk processing into fibers occurs. The small diameter of the most anterior region of the anterior silk gland prevented microelectrode access in this region. Using a histochemical method, the presence of active carbonic anhydrase was identified in the funnel and anterior silk gland of fifth instar larvae. The observed pH gradient collapsed upon addition of the carbonic anhydrase inhibitor methazolamide, confirming an essential role for this enzyme in pH regulation in the B. mori silk gland. Plastic embedding of whole silk glands allowed clear visualization of the morphology, including the identification of four distinct epithelial cell types in the gland and allowed correlations between silk gland morphology and silk stages of assembly related to the pH gradient. B. mori silk glands have four different epithelial cell types, one of which produces carbonic anhydrase. Carbonic anhydrase is necessary for the mechanism that generates an intraluminal pH gradient, which likely regulates the assembly of silk proteins and then the formation of fibers from soluble silk proteins. These new insights into native silk formation may lead to a more efficient production of artificial or regenerated silkworm silk fibers.

Dataset Information

Neutron structure of human carbonic anhydrase II: a hydrogen-bonded water network "switch" is observed between pH 7.8 and 10.0.

Publications

Neutron structure of human carbonic anhydrase II: a hydrogen-bonded water network "switch" is observed between pH 7.8 and 10.0.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets