The role of tryptophan in staphylococcal nuclease stability

Staphylococcal nuclease (SNase) has a single Trp residue at position 140. Circular dichroism, intrinsic and ANS-binding fluorescence, chemical titrations and enzymatic assays were used to measure the changes of its structure, stability and activities as the Trp was mutated or replaced to other posit...

Full description

Saved in:
Bibliographic Details
Published in:Biophysical chemistry 2010-10, Vol.151 (3), p.170-177
Main Authors: Hu, Hong-Yu, Wu, Ming-Chya, Fang, Huey-Jen, Forrest, Michael D., Hu, Chin-Kun, Tsong, Tian Yow, Chen, Hueih Min
Format: Article
Language:English
Subjects:
Anilino Naphthalenesulfonates - metabolism
Bromosuccinimide - metabolism
Circular Dichroism
Enzyme Stability
F61W/W140A
Guanidine - pharmacology
Local hydrophobicity
Micrococcal Nuclease - chemistry
Micrococcal Nuclease - genetics
Micrococcal Nuclease - metabolism
Models, Molecular
Mutagenesis, Site-Directed
Mutation
Protein Conformation
Protein Unfolding - drug effects
Spectrometry, Fluorescence
Staphylococcal nuclease
Trifluoroethanol - metabolism
Tryptophan
Tryptophan modification
W140A
Y93W/W140A
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Staphylococcal nuclease (SNase) has a single Trp residue at position 140. Circular dichroism, intrinsic and ANS-binding fluorescence, chemical titrations and enzymatic assays were used to measure the changes of its structure, stability and activities as the Trp was mutated or replaced to other positions. The results show that W140 is critical to SNase structure, stability, and function. Mutants such as W140A, F61W/W140A, and Y93W/W140A have unfolding, corrupted secondary and tertiary structures, diminished structural stability and attenuated catalytic activity as compared to the wild type. The deleterious effects of W140 substitution cannot be compensated by concurrent changes at topographical locations of position 61 or 93. Local hydrophobicity defined as a sum of hydrophobicity around a given residue within a distance is found to be a relevant property to SNase folding and stability. Changes of the Local hydrophobicity in mutants with respect to the WT SNase for W140A, F61W/W140A, and Y93W/W140A. [Display omitted]
ISSN:0301-4622
1873-4200
DOI:10.1016/j.bpc.2010.07.001