Protein internal flexibility and global stability: effect of urea on hydrogen exchange rates of bovine pancreatic trypsin inhibitor.


Abstract

The hydrogen isotope exchange kinetics of buried NH protons in bovine pancreatic trypsin inhibitor (BPTI) was measured in 8 M urea at 30 degrees C and pH 3.5. The data were analyzed by the two-process model in which slower exchanging protons utilize an unfolding mechanism and more rapidly exchanging protons exchange from the folded state. Urea accelerates the set of protons exchanging by the unfolding mechanism, all of which have approximately the same exchange rate constants in urea. For protons in this set, the ratio of exchange rate constants in the presence and absence of urea is used to estimate delta delta G(0-->8M urea) = 6.6 kcal/mol. For the set of protons exchanging from the folded state, 8 M urea either has no effect or slows exchange. Slowing of exchange by urea implies binding of urea to sites at or near the exchanging proton. Some buried protons exchanging from the folded state have diminished rates in 8 M urea, meaning that urea is accessible to these buried sites. Several unassigned side-chain NH's of arginine or lysine are highly protected from exchange by urea, suggesting that they are the location of urea binding sites on the surface of the molecule. Study holds ProTherm entries: 4548 Extra Details: hydrogen isotope exchange kinetics; unfolding mechanism;,buried protons; urea binding sites; surface

Submission Details

ID: niT8MPTL

Submitter: Connie Wang

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

Version: 1

Publication Details
Kim KS;Woodward C,Biochemistry (1993) Protein internal flexibility and global stability: effect of urea on hydrogen exchange rates of bovine pancreatic trypsin inhibitor. PMID:7690588
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
1AAL 1992-04-09T00:00:00+0000 1.6 STRUCTURAL EFFECTS INDUCED BY MUTAGENESIS AFFECTED BY CRYSTAL PACKING FACTORS: THE STRUCTURE OF A 30-51 DISULFIDE MUTANT OF BASIC PANCREATIC TRYPSIN INHIBITOR
1B0C 1998-11-06T00:00:00+0000 2.8 EVIDENCE OF A COMMON DECAMER IN THREE CRYSTAL STRUCTURES OF BPTI, CRYSTALLIZED FROM THIOCYANATE, CHLORIDE OR SULFATE
1BHC 1998-06-05T00:00:00+0000 2.7 BOVINE PANCREATIC TRYPSIN INHIBITOR CRYSTALLIZED FROM THIOCYANATE
1BPI 1995-02-18T00:00:00+0000 1.09 THE STRUCTURE OF BOVINE PANCREATIC TRYPSIN INHIBITOR AT 125K: DEFINITION OF CARBOXYL-TERMINAL RESIDUES GLYCINE-57 AND ALANINE-58
1BPT 1991-12-11T00:00:00+0000 2.0 CREVICE-FORMING MUTANTS OF BPTI: CRYSTAL STRUCTURES OF F22A, Y23A, N43G, AND F45A
1BRB 1992-12-17T00:00:00+0000 2.1 CRYSTAL STRUCTURES OF RAT ANIONIC TRYPSIN COMPLEXED WITH THE PROTEIN INHIBITORS APPI AND BPTI
1BTH 1996-12-03T00:00:00+0000 2.3 STRUCTURE OF THROMBIN COMPLEXED WITH BOVINE PANCREATIC TRYPSIN INHIBITOR
1BTI 1991-07-11T00:00:00+0000 2.2 CREVICE-FORMING MUTANTS IN THE RIGID CORE OF BOVINE PANCREATIC TRYPSIN INHIBITOR: CRYSTAL STRUCTURES OF F22A, Y23A, N43G, AND F45A
1BZ5 1998-11-05T00:00:00+0000 2.58 EVIDENCE OF A COMMON DECAMER IN THREE CRYSTAL STRUCTURES OF BPTI, CRYSTALLIZE FROM THIOCYANATE, CHLORIDE OR SULFATE
1BZX 1998-11-05T00:00:00+0000 2.1 THE CRYSTAL STRUCTURE OF ANIONIC SALMON TRYPSIN IN COMPLEX WITH BOVINE PANCREATIC TRYPSIN INHIBITOR

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Pancreatic trypsin inhibitor P00974 BPT1_BOVIN
91.0 Pancreatic trypsin inhibitor P04815 BPT2_BOVIN
91.4 Pancreatic trypsin inhibitor P00975 IBPS_BOVIN