Document Detail


Increased protein structural resolution from diethylpyrocarbonate-based covalent labeling and mass spectrometric detection.
MedLine Citation:
PMID:  22298289     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Covalent labeling and mass spectrometry are seeing increased use together as a way to obtain insight into the 3-dimensional structure of proteins and protein complexes. Several amino acid specific (e.g., diethylpyrocarbonate) and non-specific (e.g., hydroxyl radicals) labeling reagents are available for this purpose. Diethylpyrocarbonate (DEPC) is a promising labeling reagent because it can potentially probe up to 30% of the residues in the average protein and gives only one reaction product, thereby facilitating mass spectrometric analysis. It was recently reported, though, that DEPC modifications are labile for some amino acids. Here, we show that label loss is more significant and widespread than previously thought, especially for Ser, Thr, Tyr, and His residues, when relatively long protein digestion times are used. Such label loss ultimately decreases the amount of protein structural information that is obtainable with this reagent. We find, however, that the number of DEPC modified residues and, thus, protein structural information, can be significantly increased by decreasing the time between the covalent labeling reaction and the mass spectrometric analysis. This is most effectively accomplished using short (e.g., 2 h) proteolytic digestions with enzymes such as immobilized chymotrypsin or Glu-C rather than using methods (e.g., microwave or ultrasonic irradiation) that accelerate proteolysis in other ways. Using short digestion times, we show that the percentage of solvent accessible residues that can be modified by DEPC increases from 44% to 67% for cytochrome c, 35% to 81% for myoglobin, and 76% to 95% for β-2-microglobulin. In effect, these increased numbers of modified residues improve the protein structural resolution available from this covalent labeling method. Compared with typical overnight digestion conditions, the short digestion times decrease the average distance between modified residues from 11 to 7 Å for myoglobin, 13 to 10 Å for cytochrome c, and 9 to 8 Å for β-2-microglobulin.
Authors:
Yuping Zhou; Richard W Vachet
Related Documents :
20186119 - Expression of recombinant proteins in the methylotrophic yeast pichia pastoris.
135819 - Evidence for the presence of nasal salt glands in the roadrunner and the coturnix quail.
20478539 - A yersinia effector protein promotes virulence by preventing inflammasome recognition o...
21739999 - Physico-chemical and flavor characteristics of flavoring agent from mungbean protein hy...
18288539 - Comparison of electrophoretic protein profiles from sheep and goat parotid saliva.
21114309 - Protein folding and confinement: inherent structure analysis of chaperonin action.
14687579 - Identification of protein-protein interaction sites from docking energy landscapes.
15020779 - Target-assisted iterative screening of phage surface display cdna libraries.
21251859 - Expression of 14-3-3 σ protein in normal and neoplastic canine mammary gland.
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Journal of the American Society for Mass Spectrometry     Volume:  23     ISSN:  1879-1123     ISO Abbreviation:  J. Am. Soc. Mass Spectrom.     Publication Date:  2012 Apr 
Date Detail:
Created Date:  2012-04-20     Completed Date:  2012-06-28     Revised Date:  2013-05-20    
Medline Journal Info:
Nlm Unique ID:  9010412     Medline TA:  J Am Soc Mass Spectrom     Country:  United States    
Other Details:
Languages:  eng     Pagination:  708-17     Citation Subset:  IM    
Affiliation:
Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Amino Acid Sequence
Diethyl Pyrocarbonate / chemistry*
Mass Spectrometry / methods*
Molecular Sequence Data
Protein Conformation
Proteins / chemistry*
Grant Support
ID/Acronym/Agency:
R01 GM075092/GM/NIGMS NIH HHS; R01 GM075092-07/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Proteins; 1609-47-8/Diethyl Pyrocarbonate
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Polar Aprotic Modifiers for Chromatographic Separation and Back-Exchange Reduction for Protein Hydro...
Next Document:  Retention Time Alignment of LC/MS Data by a Divide-and-Conquer Algorithm.