|1mbn, resolution 2.00Å ()|
The stereochemistry of the protein myoglobin
Circular dichroism (CD) spectroscopy is an important technique in structural biology for examining folding and conformational changes of proteins in solution. However, the use of CD spectroscopy in a membrane medium (and also in a nonhomogeneous medium) is limited by (i) high light scattering and (ii) differential scattering of incident left and right circularly polarized light, especially at shorter wavelengths (<200 nm). We report a novel methodology for estimating the distortion of CD spectra caused by light scattering for membrane-bound peptides and proteins. The method is applied to three proteins with very different secondary structures to illustrate the limits of its capabilities when calibrated with a simple soluble peptide ([Ac]ANLKALEAQKQKEQRQAAEELANAK[OH], standard peptide) with a balanced secondary structure. The method with this calibration standard was quite successful in estimating alpha-helix but more limited when it comes to proteins with very high beta-sheet or beta-turn content.
A simple method for correction of circular dichroism spectra obtained from membrane-containing samples., Chakraborty H, Lentz BR, Biochemistry. 2012 Feb 7;51(5):1005-8. Epub 2012 Jan 27. PMID:022264128
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1mbn is a 1 chain structure with sequence from Physeter catodon. The January 2000 RCSB PDB Molecule of the Month feature on Myoglobin by David S. Goodsell is 10.2210/rcsb_pdb/mom_2000_1. The October 2011 RCSB PDB Molecule of the Month feature on PDB Pioneers by David Goodsell is 10.2210/rcsb_pdb/mom_2011_10. Full crystallographic information is available from OCA.