Contribution of hydrogen bonds to the conformational stability of human lysozyme: calorimetry and X-ray analysis of six tyrosine --> phenylalanine mutants.


Abstract

The contribution of hydrogen bonds to the conformational stability of human lysozyme was investigated by the combination of calorimetric and X-ray analyses of six Tyr --> Phe mutants. Unfolding Delta G and unfolding Delta H values of the Tyr --> Phe mutant proteins were changed by from +0.3 to -4.0 kJ/mol and from 0 to -16 kJ/mol, respectively, compared to those of the wild-type protein. The net contribution of a hydrogen bond at a specific site to stability (Delta Gwild/HB), considering factors affected by substitutions, was evaluated on the basis of X-ray structures of the mutant proteins. In the present study, one of six mutant proteins was suitable for evaluating the strength of the hydrogen bond. Delta Gwild/HB for the intramolecular hydrogen bond at Tyr124 was evaluated to be 7.5 kJ/mol. Results of the analysis of other mutants also suggest that hydrogen bonds of the hydroxyl group of Tyr, including the hydrogen bond with a water molecule, contribute to the stabilization of the human lysozyme. Study holds ProTherm entries: 3399, 3400, 3401, 3402, 3403, 3404, 3405, 4189, 4190, 4191, 4192, 4193, 4194, 4195, 4196, 4197, 4198, 4199, 4200, 4201, 4202, 4203, 4204, 4205, 4206, 4207, 4208, 4209, 4210, 4211, 4212, 4213, 4214, 14203, 14204, 14205, 14206, 14207, 14208 Extra Details: conformational stability; hydrogen bonds; tyrosine;,phenylalanine; human lysozyme

Submission Details

ID: Umgda4Vs

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:21 p.m.

Version: 1

Publication Details
Yamagata Y;Kubota M;Sumikawa Y;Funahashi J;Takano K;Fujii S;Yutani K,Biochemistry (1998) Contribution of hydrogen bonds to the conformational stability of human lysozyme: calorimetry and X-ray analysis of six tyrosine --> phenylalanine mutants. PMID:9649316
Additional Information

Number of data points 151
Proteins Lysozyme C ; Lysozyme C ; Lysozyme C ; Lysozyme C ; Lysozyme C ; Lysozyme C ; Lysozyme C ; Lysozyme C
Unique complexes 7
Assays/Quantities/Protocols Experimental Assay: dCp ionic:-: -, temp:64.9 C ; Experimental Assay: ddG ; Experimental Assay: dCp pH:2.53, ionic:: ; Experimental Assay: dHcal pH:2.53 ; Experimental Assay: Tm pH:2.53 ; Experimental Assay: dHvH pH:2.53 ; Experimental Assay: dCp pH:2.68, ionic:: ; Experimental Assay: dHcal pH:2.68 ; Experimental Assay: Tm pH:2.68 ; Experimental Assay: dHvH pH:2.68 ; Experimental Assay: dCp ionic:: , pH:2.73 ; Experimental Assay: dHcal pH:2.73 ; Experimental Assay: Tm pH:2.73 ; Experimental Assay: dHvH pH:2.73 ; Experimental Assay: dCp pH:3.0, ionic:: ; Experimental Assay: dHcal pH:3.0 ; Experimental Assay: Tm pH:3.0 ; Experimental Assay: dHvH pH:3.0 ; Experimental Assay: dCp pH:3.17, ionic:: ; Experimental Assay: dHcal pH:3.17 ; Experimental Assay: Tm pH:3.17 ; Experimental Assay: dHvH pH:3.17 ; Experimental Assay: dCp pH:2.69, ionic:: ; Experimental Assay: dHcal pH:2.69 ; Experimental Assay: Tm pH:2.69 ; Experimental Assay: dHvH pH:2.69 ; Experimental Assay: dCp pH:2.82, ionic:: ; Experimental Assay: dHcal pH:2.82 ; Experimental Assay: Tm pH:2.82 ; Experimental Assay: dHvH pH:2.82 ; Experimental Assay: dCp pH:2.99, ionic:: ; Experimental Assay: dHcal pH:2.99 ; Experimental Assay: Tm pH:2.99 ; Experimental Assay: dHvH pH:2.99 ; Experimental Assay: dCp pH:2.48, ionic:: ; Experimental Assay: dHcal pH:2.48 ; Experimental Assay: Tm pH:2.48 ; Experimental Assay: dHvH pH:2.48 ; Experimental Assay: dCp ionic:: , pH:2.67 ; Experimental Assay: dHcal pH:2.67 ; Experimental Assay: Tm pH:2.67 ; Experimental Assay: dHvH pH:2.67 ; Experimental Assay: dCp pH:3.13, ionic:: ; Experimental Assay: dHcal pH:3.13 ; Experimental Assay: Tm pH:3.13 ; Experimental Assay: dHvH pH:3.13 ; Experimental Assay: dCp pH:2.71, ionic:: ; Experimental Assay: dHcal pH:2.71 ; Experimental Assay: Tm pH:2.71 ; Experimental Assay: dHvH pH:2.71 ; Experimental Assay: dCp pH:2.92, ionic:: ; Experimental Assay: dHcal pH:2.92 ; Experimental Assay: Tm pH:2.92 ; Experimental Assay: dHvH pH:2.92 ; Experimental Assay: dCp pH:3.1, ionic:: ; Experimental Assay: dHcal pH:3.1 ; Experimental Assay: Tm pH:3.1 ; Experimental Assay: dHvH pH:3.1 ; Experimental Assay: dCp ionic:: , pH:3.25 ; Experimental Assay: dHcal pH:3.25 ; Experimental Assay: Tm pH:3.25 ; Experimental Assay: dHvH pH:3.25 ; Experimental Assay: dCp pH:2.58, ionic:: ; Experimental Assay: dHcal pH:2.58 ; Experimental Assay: Tm pH:2.58 ; Experimental Assay: dHvH pH:2.58 ; Experimental Assay: dCp pH:2.74, ionic:: ; Experimental Assay: dHcal pH:2.74 ; Experimental Assay: Tm pH:2.74 ; Experimental Assay: dHvH pH:2.74 ; Experimental Assay: dCp pH:2.89, ionic:: ; Experimental Assay: dHcal pH:2.89 ; Experimental Assay: Tm pH:2.89 ; Experimental Assay: dHvH pH:2.89 ; Experimental Assay: dCp pH:3.06, ionic:: ; Experimental Assay: dHcal pH:3.06 ; Experimental Assay: Tm pH:3.06 ; Experimental Assay: dHvH pH:3.06 ; Experimental Assay: dCp pH:3.18, ionic:: ; Experimental Assay: dHcal pH:3.18 ; Experimental Assay: Tm pH:3.18 ; Experimental Assay: dHvH pH:3.18 ; Experimental Assay: dTm ; Experimental Assay: dHcal pH:2.7 ; Experimental Assay: Tm pH:2.7 ; Experimental Assay: dHvH pH:2.7 ; Experimental Assay: dCp ionic::
Libraries Mutations for sequence KVFERCELARTLKRLGMDGYRGISLANWMCLAKWESGYNTRATNYNAGDRSTDYGIFQINSRYWCNDGKTPGAVNACHLSCSALLQDNIADAVACAKRVVRDPQGIRAWVAWRNRCQNRDVRQYVQGCGV
Sequence Assay Result Units