Effect of signal peptide on the stability and folding kinetics of maltose binding protein.


While the role of the signal sequence in targeting proteins to specific subcellular compartments is well characterized, there are fewer studies that characterize its effects on the stability and folding kinetics of the protein. We report a detailed characterization of the folding kinetics and thermodynamic stabilities of maltose binding protein (MBP) and its precursor form, preMBP. Isothermal GdmCl and urea denaturation as a function of temperature and thermal denaturation studies have been carried out to compare stabilities of the two proteins. preMBP was found to be destabilized by about 2-6 kcal/mol (20-40%) with respect to MBP. Rapid cleavage of the signal peptide by various proteases shows that the signal peptide is accessible in the native form of preMBP. The observed rate constant of the major slow phase in folding was decreased 5-fold in preMBP relative to MBP. The rate constants of unfolding were similar at 25 degrees C, but preMBP also exhibited a large burst phase change in unfolding that was absent in MBP. At 10 degrees C, preMBP exhibited a higher unfolding rate than MBP as well as a large burst phase. The appreciable destabilization of MBP by signal peptide is functionally relevant, because it enhances the likelihood of finding the protein in an unfolded translocation-competent form and may influence the interactions of the protein with the translocation machinery. Destabilization is likely to result from favorable interactions between the hydrophobic signal peptide and other hydrophobic regions that are exposed in the unfolded state. Study holds ProTherm entries: 16948, 16949, 16950, 16951, 16952, 16953, 16954, 16955, 16956, 16957, 16958, 16959, 16960, 16961, 16962, 16963, 16964, 16965, 16966, 16967, 16968, 16969, 16970, 16971 Extra Details: signal sequence; folding kinetics; rate constant; hydrophobic

Submission Details

ID: S548wgF34

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:48 p.m.

Version: 1

Publication Details
Beena K;Udgaonkar JB;Varadarajan R,Biochemistry (2004) Effect of signal peptide on the stability and folding kinetics of maltose binding protein. PMID:15035631
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 UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Maltose-binding periplasmic protein P0AEY0 MALE_ECO57
100.0 Maltose-binding periplasmic protein P0AEX9 MALE_ECOLI
94.3 Maltose-binding periplasmic protein P19576 MALE_SALTY
93.9 Maltose-binding periplasmic protein P18815 MALE_KLEAE
90.7 Maltose-binding periplasmic protein P41130 MALE_PHOLU