1V1D
Nucleophilic and General Acid Catalysis at Physiological pH by a Designed Miniature Esterase
Summary for 1V1D
| Entry DOI | 10.2210/pdb1v1d/pdb |
| Related | 1BBA 1LJV |
| Descriptor | PANCREATIC HORMONE (1 entity in total) |
| Functional Keywords | hormone, cleavage on pair of basic residues, pancreas |
| Biological source | BOS TAURUS (BOVINE) |
| Cellular location | Secreted: P01302 |
| Total number of polymer chains | 1 |
| Total formula weight | 3688.11 |
| Authors | Nicoll, A.,Allemann, R.K. (deposition date: 2004-04-14, release date: 2005-04-14, Last modification date: 2024-05-15) |
| Primary citation | Nicoll, A.,Allemann, R.K. Nucleophilic and General Acid Catalysis at Physiological Ph by a Designed Miniature Esterase Org.Biomol.Chem., 2:2175-, 2004 Cited by PubMed Abstract: A 31-residue peptide (Art-Est) was designed to catalyse the hydrolysis of p-nitrophenyl esters through histidine catalysis on the solvent exposed face of the alpha-helix of bovine pancreatic polypeptide. NMR spectroscopy indicated that Art-Est adopted a stable 3-dimensional structure in solution. Art-Est was an efficient catalyst with second order rate constants of up to 0.050 M(-1) s(-1). The activity of Art-Est was a consequence of the increased nucleophilicity of His-22, which had a reduced pK(a) value of 5.5 as a consequence of its interaction with His-18 and the positively charged Arg-25 and Arg-26. Mass spectrometry and NMR spectroscopy confirmed that the Art-Est catalysed hydrolysis of p-nitrophenyl esters proceeded through an acyl-enzyme intermediate. A solvent kinetic isotope effect of 1.8 indicated that the transition state preceding the acyl intermediate was stabilised through interaction with the protonated side-chain of His-18 and indicated a reaction mechanism similar to that generally observed for natural esterases. The involvement in the reaction of two histidine residues with different pK(a) values led to a bell-shaped dependence of the reaction rate on the pH of the solution. The catalytic behaviour of Art-Est indicated that designed miniature enzymes can act in a transparent mechanism based fashion with enzyme-like behaviour through the interplay of several amino acid residues. PubMed: 15280952DOI: 10.1039/B404730C PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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