V92A mutation altered the folding propensity of chicken apocytochrome c and its interaction with phospholipids.


Chicken apocytochrome c has been shown to possess a much stronger tendency to fold spontaneously in aqueous solution than the equivalent enzyme from other species. In the present work, the amino acid that determines its folding ability was elucidated by site-directed mutagenesis. Wild-type chicken apocytochrome c and three mutants V92A, S103A, and V92A/S103A were expressed in Escherichia coli. The wild-type apoprotein and S103A exhibited the same folding property during dialysis renaturation processes as that chemically prepared from chicken cytochrome c, while those containing V92A mutation did not. Quantitative studies by 2,2,2-trifluoroethanol (TFE) and sodium perchlorate (NaClO4) titration demonstrated that the V92A mutation decreased the helix content that could be induced and confirmed that valine 92 is the major determinant of the folding propensity of chicken apocytochrome c. Furthermore, CD spectra, turbidity measurements, and a translocation assay on a model membrane system showed that the V92A mutation also drastically altered the conformation of apocytochrome c after being incorporated into lipid bilayer and decreased the aggregation of phospholipid vesicles after association of the apoprotein, thus rendering the molecule more competent for translocation across the membrane. Our results showed that a single amino acid substitution could radically alter the folding propensity of an unfolded polypeptide chain and thus influence the conformation following its insertion into phospholipid bilayer. Study holds ProTherm entries: 4670, 4671, 4672 Extra Details: folding ability; dialysis renaturation; helix content;,model membrane system; phospholipid bilayer

Submission Details

ID: HaJ9DfuB

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:26 p.m.

Version: 1

Publication Details
Tong JC;Zhu LQ;Yang FY,Biochemistry (1996) V92A mutation altered the folding propensity of chicken apocytochrome c and its interaction with phospholipids. PMID:8755725
Additional Information

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 UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Cytochrome c P67881 CYC_CHICK
100.0 Cytochrome c P67882 CYC_MELGA
98.1 Cytochrome c P00017 CYC_APTPA
97.1 Cytochrome c P00020 CYC_ANAPL
98.1 Cytochrome c P00018 CYC_DRONO
98.1 Cytochrome c P00019 CYC_STRCA
96.2 Cytochrome c P00021 CYC_COLLI
92.4 Cytochrome c P00022 CYC_CHESE
92.4 Cytochrome c P62897 CYC_MOUSE
92.4 Cytochrome c P62898 CYC_RAT
92.4 Cytochrome c P00008 CYC_RABIT
91.4 Cytochrome c P68099 CYC_CAMDR
91.4 Cytochrome c P68100 CYC_ESCRO
91.4 Cytochrome c P68098 CYC_LAMGU
91.4 Cytochrome c P62894 CYC_BOVIN
90.5 Cytochrome c P00007 CYC_HIPAM
91.4 Cytochrome c P62895 CYC_PIG
91.4 Cytochrome c P62896 CYC_SHEEP
91.4 Cytochrome c Q52V09 CYC_CEPBA
91.3 Cytochrome c P81280 CYC_ALLMI
91.4 Cytochrome c P21665 CYC_VARVA
90.5 Cytochrome c P00011 CYC_CANLF
91.3 Cytochrome c Q6DKE1 CYC2_XENLA
90.5 Cytochrome c P68097 CYC_EQUAS
90.5 Cytochrome c P68096 CYC_EQUBU
90.5 Cytochrome c P00013 CYC_MINSC
90.5 Cytochrome c P00012 CYC_MIRLE
91.3 Cytochrome c Q6PBF4 CYC2_XENTR