title: On the role of protein structural dynamics in the catalytic activity and thermostability of serine protease subtilisin Carlsberg.
abstract: The effect of structural dynamics on enzyme activity and thermostability has thus far only been investigated in detail for the serine protease alpha-chymotrypsin (for a recent review see Solá et al., Cell Mol Life Sci 2007, 64(16): 2133-2152). Herein, we extend this type of study to a structurally unrelated serine protease, specifically, subtilisin Carlsberg. The protease was incrementally glycosylated with chemically activated lactose to obtain various subtilisin glycoconjugates which were biophysically characterized. Near UV-CD spectroscopy revealed that the tertiary structure was unaffected by the glycosylation procedure. H/D exchange FT-IR spectroscopy was performed to assess the changes in structural dynamics of the enzyme. It was found that increasing the level of glycosylation caused a linearly dependent reduction in structural dynamics. This led to an increase in thermostability and a decrease in the catalytic turnover rate for both, the enzyme acylation and deacylation steps. These results highlight the possibility that a structural dynamics-activity relationship might be a phenomenon generally found in serine proteases.
authors.affiliation: Department of Chemistry, University of Puerto Rico, Río Piedras Campus, PO Box 23346, San Juan 00931-3346, Puerto Rico.
authors.forename: Miraida
authors.initials: M
authors.lastname: Pagán
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: Solá
authors.forename: Kai
authors.initials: K
authors.lastname: Griebenow
mesh_terms: D002942:Circular Dichroism; D004795:Enzyme Stability; D006031:Glycosylation; D007700:Kinetics; D008958:Models, Molecular; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D017550:Spectroscopy, Fourier Transform Infrared; D013381:Subtilisins / Q000737:chemistry* / Q000378:metabolism*; D013696:Temperature
chemical_list: D013381:Subtilisins