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Influence of enzyme conformational changes on catalytic activity investigated by circular dichroism spectroscopy
Author(s) -
Rigos Carolina Fortes,
Santos Hérica de Lima,
Thedei Geraldo,
Ward Richard John,
Ciancaglini Pietro
Publication year - 2003
Publication title -
biochemistry and molecular biology education
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.34
H-Index - 39
eISSN - 1539-3429
pISSN - 1470-8175
DOI - 10.1002/bmb.2003.494031050264
Subject(s) - circular dichroism , random coil , chemistry , denaturation (fissile materials) , guanidinium chloride , enzyme , conformational change , substrate (aquarium) , protein secondary structure , helix (gastropod) , protein structure , enzyme assay , crystallography , biophysics , stereochemistry , biochemistry , biology , snail , nuclear chemistry , oceanography , geology , ecology
Enzyme activity is dependent on native conformational integrity. Here we present a simple laboratory exercise based on dichroism spectroscopy in which the change in enzyme structure induced by denaturation is correlated with the loss of catalytic activity. The results of circular dichroism spectra show that enzyme denaturation by either trifluoroethanol (enhancement of α‐helix structure) or guanidinium chloride (reduction of α‐helix and enhancement of random coil structure) leads to a concomitant reduction in enzyme activity, which demonstrates the relationship between structure and catalytic activity of the enzyme. This simple experimental approach demonstrates that only a single native protein (enzyme) conformation has the ability to catalyze substrate hydrolysis.