Stanford University2015-01-09 3:26 PM

Extreme electric fields power catalysis in the active site of ketosteroid isomerase

Abstract


Enzymes use protein architecture to impose specific electrostatic fields onto their bound substrates, but the magnitude and catalytic effect of these electric fields have proven difficult to quantify with standard experimental approaches. Using vibrational Stark effect spectroscopy, we found that the active site of the enzyme ketosteroid isomerase (KSI) exerts an extremely large electric field onto the C=O chemical bond that undergoes a charge rearrangement in KSI’s rate-determining step. Moreover, we found that the magnitude of the electric field exerted by the active site strongly correlates with the enzyme’s catalytic rate enhancement, enabling us to quantify the fraction of the catalytic effect that is electrostatic in origin. The measurements described here may help explain the role of electrostatics in many other enzymes and biomolecular systems.


Full Article:

http://www.sciencemag.org/content/346/6216/1510.abstract

KEYWORDS

SHARE & LIKE

COMMENTS

ABOUT THE AUTHOR

Stanford University

0 Following 0 Fans 0 Projects 20 Articles

SIMILAR ARTICLES

AbstractDesorption electrospray ionization mass spectrometric imaging (DESI-MSI) has been shown to be particularly powerful for identifying lipids and

Read More

AbstractMo- and W-dichalcogenide compounds have a two-dimensional monolayer form that differs from graphene in an important respect: it can potentially

Read More

AbstractBackgroundWe still know little about whether and how the auditory hallucinations associated with serious psychotic disorder shift across cultur

Read More

Keywords:channel networks;erosional processes;symmetry;landscape evolution;random networksAbstractThe branched structure of channel networks has a prim

Read More

IntroductionOver the past three decades, the earnings of workers with a college education have substantially increased relative to those with less educ

Read More

ABSTRACTWe live amid a global wave of anthropogenically driven biodiversity loss: species and population extirpations and, critically, declines in loca

Read More

BackgroundLeber congenital amaurosis, caused by mutations in RPE65 and LRAT, is a severe form of inherited retinal degeneration leading to blindness. W

Read More

AbstractOil palm plantation expansion into tropical forests may alter physical and biogeochemical inputs to streams, thereby changing hydrological func

Read More

AbstractHummingbirds are the only birds that can sustain hovering. This unique flight behaviour comes, however, at high energetic cost. Based on helico

Read More

Abstract Measures of teachers’ “value added” to students’ current test performance feature prominently in ongoing reforms to teacher evaluation systems

Read More