Unfolding behavior of human alpha 1-acid glycoprotein is compatible with a loosely folded region in its polypeptide chain.


Abstract

The unfolding of human plasma alpha 1-acid glycoprotein (AGP) induced by heat or guanidine hydrochloride was studied under equilibrium conditions. In thermal unfolding, an intermediate state was detected by the appearance of unusual positive difference absorption bands in the 287-295-nm region, which occurred at lower temperatures than the common denaturation bands at 284 and 291 nm. The formation of this intermediate species apparently involves a local conformational change that perturbs the environment of tryptophyl residues, without affecting the secondary structure of the protein as judged from circular dichroism spectra. On the other hand, denaturation of the glycoprotein induced by guanidine hydrochloride seemed to follow a two-state model with no evidence of any intermediate species; however, the analysis of the transition curve indicated that the change in the accessibility to solvent of amino acid residues of AGP upon unfolding is significantly lower than those observed for other proteins. According to these results, it is proposed that part of the polypeptide chain in native AGP, namely, that from residue 122 to the C-terminus, may be "loosely" folded. Study holds ProTherm entries: 3674, 3675 Extra Details: loosely folded; intermediate state; local conformational change;,secondary structure; accessibility to solvent

Submission Details

ID: 8xz3bbfW3

Submitter: Connie Wang

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

Version: 1

Publication Details
Rojo-Domínguez A;Zubillaga-Luna R;Hernández-Arana A,Biochemistry (1990) Unfolding behavior of human alpha 1-acid glycoprotein is compatible with a loosely folded region in its polypeptide chain. PMID:2271550
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
3KQ0 2010-02-02 1.8 Crystal structure of human alpha1-acid glycoprotein

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Alpha-1-acid glycoprotein 1 P02763 A1AG1_HUMAN