Hydrogen exchange of the tryptophan residues in bovine, goat, guinea pig, and human alpha-lactalbumin.


Abstract

Hydrogen exchange of the individual tryptophan residues of bovine, goat, guinea pig, and human alpha-lactalbumin has been studied by both ultraviolet and NMR spectra. The assignment of the slowly exchanging imino proton resonances to the tryptophan residues (Trp26 and Trp60) was obtained by comparison of the nuclear Overhauser effect difference spectra of bovine, guinea pig, and human alpha-lactalbumin. Taking account of the thermal unfolding of each alpha-lactalbumin, the hydrogen exchange rates of the individual tryptophan residues are analyzed. The temperature dependence of the exchange rates classified their exchange mechanisms into two exchange processes: the "low activation energy process" and the "high activation energy process" which is associated directly with the global thermal unfolding of the protein. Trp26 of alpha-lactalbumin exchanges through the high activation energy process. The exchange behavior of Trp26 of guinea pig alpha-lactalbumin suggests a difference of the globally unfolded state of the protein from the other species. The exchange mechanism of Trp60 of human alpha-lactalbumin is the low activation energy process in contrast with those of the bovine and goat proteins, although their global thermodynamic properties are similar to each other. Trp104 and Trp118 of alpha-lactalbumin exchange through the low activation energy process, and the reaction rates are affected by the local structural differences around the tryptophan residues among these proteins. The results presented in this paper indicate that the hydrogen exchange rate through the low activation energy process provides the information only about the local nature of a protein while that through the high activation energy process provides the information about the global nature of a protein. Study holds ProTherm entries: 3838, 3839, 3840, 3841 Extra Details: hydrogen exchange; low activation energy process;,high activation energy; local structural differences

Submission Details

ID: wkvshAvc

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:22 p.m.

Version: 1

Publication Details
Harushima Y;Sugai S,Biochemistry (1989) Hydrogen exchange of the tryptophan residues in bovine, goat, guinea pig, and human alpha-lactalbumin. PMID:2605208
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
1CB3 1999-06-08 LOCAL INTERACTIONS DRIVE THE FORMATION OF NON-NATIVE STRUCTURE IN THE DENATURED STATE OF HUMAN ALPHA-LACTALBUMIN: A HIGH RESOLUTION STRUCTURAL CHARACTERIZATION OF A PEPTIDE MODEL IN AQUEOUS SOLUTION
1B9O 1999-03-31 1.15 HUMAN ALPHA-LACTALBUMIN, LOW TEMPERATURE FORM
3B0O 2012-06-13 1.61 Crystal structure of alpha-lactalbumin
1ALC 1989-10-15 1.7 REFINED STRUCTURE OF BABOON ALPHA-LACTALBUMIN AT 1.7 ANGSTROMS RESOLUTION. COMPARISON WITH C-TYPE LYSOZYME
1HML 1995-01-26 1.7 ALPHA_LACTALBUMIN POSSESSES A DISTINCT ZINC BINDING SITE
3B0I 2012-06-13 1.8 Crystal structure of recombinant human alpha lactalbumin
1A4V 1999-04-27 1.8 ALPHA-LACTALBUMIN
4L41 2013-10-02 2.7 Human Lactose synthase: A 2:1 complex between human alpha-lactalbumin and human beta1,4-galactosyltransferase

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
91.7 Alpha-lactalbumin P37154 LALBA_FELCA
94.3 Alpha-lactalbumin P12065 LALBA_PAPCY
100.0 Alpha-lactalbumin P00709 LALBA_HUMAN