Related Experiment Video
Updated: Oct 21, 2026

The Importance of Correct Protein Concentration for Kinetics and Affinity Determination in Structure-function Analysis
Published on: March 17, 2010
A low-barrier hydrogen bond in the catalytic triad of serine proteases? Theory versus experiment
E L Ash1, J L Sudmeier, E C De Fabo
1Department of Biochemistry, Tufts University School of Medicine, Boston, MA 02111, USA.
Abstract:
Cleland and Kreevoy recently advanced the idea that a special type of hydrogen bond (H-bond), termed a low-barrier hydrogen bond (LBHB), may account for the "missing" transition state stabilization underlying the catalytic power of many enzymes, and Frey et al. have proposed that the H-bond between aspartic acid 102 and histidine 57 in the catalytic triad of serine proteases is an example of a catalytically important LBHB. Experimental facts are here considered regarding the aspartic acid-histidine and cis-urocanic H-bonds that are inconsistent with fundamental tenets of the LBHB hypothesis. The inconsistencies between theory and experiment in these paradigm systems cast doubt on the existence of LBHBs, as currently defined, within enzyme active sites.
Related Concept Videos
Catalysis
Enzymes
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Catalytically Perfect Enzymes
Introduction to Mechanisms of Enzyme Catalysis
Introduction to Mechanisms of Enzyme Catalysis

