Thermodynamic stability of domain 2 of epithelial cadherin.


Abstract

Cadherin is a cell adhesion molecule that participates in ordered calcium-dependent self-association interactions both between molecules on the same cell surface (cis-interactions) and on neighboring cell surfaces (trans-interactions). Cadherin is a transmembrane protein that has 3-7 independently folded beta-barrel extracellular domains. Both types of self-association interactions are mediated through the most N-terminal domain (Domain 1). Although the structural nature of the trans-interactions is clear, the nature of the cis-interactions is ambiguous despite several high-resolution structural studies. From earlier studies, it is understood that for the trans-interactions to happen, cis-interactions are mandatory. Hence, our first steps are to study the energetic driving forces for the cis-interactions. We have simplified the approach by first examining participating extracellular domains individually. We report here our initial experiments into the stability of Domain 2 of E-cadherin (ECAD2). ECAD2 appears monomeric, according to results from mass spectrometry and sedimentation equilibrium studies. We report denaturation data from differential scanning calorimetric experiments, and temperature and denaturant-induced unfolding experiments monitored by circular dichroism. These studies give a unified picture of the energetics of ECAD2-folding and stability, for which DeltaG degrees is 6.6 kcal/mol, T(m) is 54 degrees C, DeltaH(m) is 90 kcal/mol, and DeltaC(p) is 1300 cal/Kmol. These parameters are independent of calcium up to 5 mM, indicating that ECAD2 does not bind calcium at physiological calcium levels. Study holds ProTherm entries: 17063, 17064, 17065, 17066, 17067, 17068, 17069, 17070 Extra Details: 20 microM EGTA was added in the experiment. calcium-dependent; transmembrane; domain; stability

Submission Details

ID: Wr5gfcBj

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:49 p.m.

Version: 1

Publication Details
Prasad A;Housley NA;Pedigo S,Biochemistry (2004) Thermodynamic stability of domain 2 of epithelial cadherin. PMID:15209501
Additional Information

Number of data points 16
Proteins Cadherin-1 ; Cadherin-1
Unique complexes 1
Assays/Quantities/Protocols Experimental Assay: m temp:42.0 C ; Experimental Assay: dG_H2O temp:42.0 C ; Experimental Assay: m temp:37.0 C ; Experimental Assay: dG_H2O temp:37.0 C ; Experimental Assay: m temp:30.0 C ; Experimental Assay: dG_H2O temp:30.0 C ; Experimental Assay: m temp:25.0 C ; Experimental Assay: dG_H2O temp:25.0 C ; Experimental Assay: dG buffers:potassium phosphate: 10 mM, details:Additives , prot_conc:to 380 microM ; Experimental Assay: dCp buffers:potassium phosphate: 10 mM, details:Additives , prot_conc:to 380 microM ; Experimental Assay: dHcal buffers:potassium phosphate: 10 mM, details:Additives , prot_conc:to 380 microM ; Experimental Assay: Tm buffers:potassium phosphate: 10 mM, details:Additives , prot_conc:to 380 microM ; Experimental Assay: dG prot_conc:5-20 microM, details:Additives EGTA (20 micro M),, buffers:HEPES: 2 mM ; Experimental Assay: dCp prot_conc:5-20 microM, details:Additives EGTA (20 micro M),, buffers:HEPES: 2 mM ; Experimental Assay: dHcal prot_conc:5-20 microM, details:Additives EGTA (20 micro M),, buffers:HEPES: 2 mM ; Experimental Assay: Tm prot_conc:5-20 microM, details:Additives EGTA (20 micro M),, buffers:HEPES: 2 mM
Libraries Mutations for sequence MRDWVIPPISCPENEKGEFPKNLVQIKSNRDKETKVFYSITGQGADKPPVGVFIIERETGWLKVTQPLDREAIAKYILYSHAVSSNGEAVEDPMEIVITVTDQNDNRPEFTQEVFEGSVAEGAVPGTSVMKVSATDADDDVNTYNAAIAYTIVSQDPELPHKNMFTVNRDTGVISVLTSGLDRESYPTYTLVVQAADLQGEGLSTTAKAVITVKDINDNAPVFNPS
Sequence Assay Result Units