Role of amino-terminal residues in the folding of the constant fragment of the immunoglobulin light chain.


Abstract

Three constant fragments with different amino terminals, CL(105-214), CL(109-214), and CL(113-214), were obtained by limited proteolysis with trypsin or papain of a type lambda immunoglobulin light chain. The conformations of the three CL fragments were indistinguishable on the basis of circular dichroism and tryptophyl fluorescence spectra. The stability to heat and guanidine hydrochloride of CL(105-214) was almost the same as that of CL(109-214), but the stability of CL(113-214) was slightly lower than that of CL(105-214) or CL(109-214). The midpoint of the thermal unfolding transition at pH 7.5 was at 60.0 degrees C for CL(105-214), 60.4 degrees C for CL(109-214), and 57.5 degrees C for CL(113-214). The midpoint of the unfolding transition by guanidine hydrochloride at pH 7.5 and 25 degrees C was 1.2 M for CL(105-214) and CL(109-214) and at 1.0 M for CL(113-214). The kinetics of unfolding and refolding by guanidine hydrochloride of these CL fragments were analyzed on the basis of the three-species mechanism, U1 in equilibrium with U2 in equilibrium with N, where U1 and U2 are the slow-folding and fast-folding species, respectively, of unfolded protein and N is native protein. It was found that only the microscopic unfolding rate constant for CL(113-214) is 2-3 times greater than that for CL(105-214) or CL(109-214) and that the other microscopic rate constants for the three CL fragments are all the same. These findings indicated that the amino-terminal residues, Gly-109-Lys-112, or a part of them, stabilize the CL(113-214) fragment by decreasing only the unfolding rate, that the transition state of the folding of the CL fragment is independent of the presence or absence of this peptide, and that, at the last step of folding, the peptide is incorporated into the globular domain, thus stabilizing it. Study holds ProTherm entries: 3962, 3963, 3964, 3965, 3966, 3968, 3969, 3970 Extra Details: amino-terminal residues; constant fragments;,microscopic rate constants; transition state

Submission Details

ID: nHWRF8333

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:23 p.m.

Version: 1

Publication Details
Goto Y;Hamaguchi K,Biochemistry (1987) Role of amino-terminal residues in the folding of the constant fragment of the immunoglobulin light chain. PMID:3109473
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
1AR2 1997-08-08T00:00:00+0000 2.8 DISULFIDE-FREE IMMUNOGLOBULIN FRAGMENT
1BWW 1998-09-29T00:00:00+0000 1.7 BENCE-JONES IMMUNOGLOBULIN REI VARIABLE PORTION, T39K MUTANT
1REI 1976-03-17T00:00:00+0000 2.0 THE MOLECULAR STRUCTURE OF A DIMER COMPOSED OF THE VARIABLE PORTIONS OF THE BENCE-JONES PROTEIN REI REFINED AT 2.0 ANGSTROMS RESOLUTION
1WTL 1994-06-08T00:00:00+0000 1.9 COMPARISON OF CRYSTAL STRUCTURES OF TWO HOMOLOGOUS PROTEINS: STRUCTURAL ORIGIN OF ALTERED DOMAIN INTERACTIONS IN IMMUNOGLOBULIN LIGHT CHAIN DIMERS
4L1H 2013-06-03T00:00:00+0000 1.68 Bence-Jones immunoglobulin REI variable portion with seven point mutations
5XP1 2017-05-31T00:00:00+0000 2.88 Structure of monomeric mutant of REI immunoglobulin light chain variable domain crystallized at pH 6
1EEQ 2000-02-01T00:00:00+0000 1.5 M4L/Y(27D)D/T94H Mutant of LEN
1EEU 2000-02-03T00:00:00+0000 1.6 M4L/Y(27D)D/Q89D/T94H mutant of LEN
1EFQ 2000-02-09T00:00:00+0000 1.6 Q38D mutant of LEN
1EK3 2000-03-06T00:00:00+0000 1.9 KAPPA-4 IMMUNOGLOBULIN VL, REC

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Immunoglobulin kappa variable 1D-33 P01593 KVD33_HUMAN
100.0 Immunoglobulin kappa variable 1D-33 P01594 KV133_HUMAN
99.0 Immunoglobulin kappa variable 4-1 P06312 KV401_HUMAN