TY - JOUR
T1 - Atomic resolution crystallography reveals how changes in pH shape the protein microenvironment
AU - Lyubimov, A.Y.
AU - Lario, P.I.
AU - Moustafa, I.
AU - Vrielink, Alice
PY - 2006
Y1 - 2006
N2 - Hydrogen atoms are a vital component of enzyme structureand function1–4. In recent years, atomic resolutioncrystallography (Z1.2 A°) has been successfully used toinvestigate the role of the hydrogen atom in enzymaticcatalysis5–9. Here, atomic resolution crystallography wasused to study the effect of pH on cholesterol oxidase fromStreptomyces sp., a flavoenzyme oxidoreductase.Crystallographic observations of the anionic oxidized flavincofactor at basic pH are consistent with the UV-visibleabsorption profile of the enzyme and readily explainthe reversible pH-dependent loss of oxidation activity.Furthermore, a hydrogen atom, positioned at an unusuallyshort distance from the main chain carbonyl oxygen ofMet122 at high pH, was observed, suggesting a previouslyunknown mechanism of cofactor stabilization. This studyshows how a redox active site responds to changes in theenzyme’s environment and how these changes are able toinfluence the mechanism of enzymatic catalysis.
AB - Hydrogen atoms are a vital component of enzyme structureand function1–4. In recent years, atomic resolutioncrystallography (Z1.2 A°) has been successfully used toinvestigate the role of the hydrogen atom in enzymaticcatalysis5–9. Here, atomic resolution crystallography wasused to study the effect of pH on cholesterol oxidase fromStreptomyces sp., a flavoenzyme oxidoreductase.Crystallographic observations of the anionic oxidized flavincofactor at basic pH are consistent with the UV-visibleabsorption profile of the enzyme and readily explainthe reversible pH-dependent loss of oxidation activity.Furthermore, a hydrogen atom, positioned at an unusuallyshort distance from the main chain carbonyl oxygen ofMet122 at high pH, was observed, suggesting a previouslyunknown mechanism of cofactor stabilization. This studyshows how a redox active site responds to changes in theenzyme’s environment and how these changes are able toinfluence the mechanism of enzymatic catalysis.
U2 - 10.1038/nchembio0606-346a
DO - 10.1038/nchembio0606-346a
M3 - Article
SN - 1552-4450
VL - 2
SP - 259
EP - 264
JO - Nature Chemical Biology
JF - Nature Chemical Biology
IS - 5
ER -