TY - JOUR
T1 - Stability studies of extracellular domain two of neural-cadherin
AU - Vunnam, Nagamani
AU - McCool, John K.
AU - Williamson, Michael
AU - Pedigo, Susan
N1 - Funding Information:
This research was supported by MCB 0950494 from the National Science Foundation.
PY - 2011/12
Y1 - 2011/12
N2 - Neural- (NCAD) and epithelial- (ECAD) cadherin are calcium-dependent cell-adhesive molecules, and are localized at excitatory and inhibitory synapses respectively. They play an important role in synaptogenesis, synapse maintenance and plasticity. The extracellular region plays a critical role in cadherin-mediated cell adhesion, and has five tandemly repeated ectodomains (EC1-EC5). Calcium binding is required for dimer formation between first two N-terminal domains (EC1-EC2). Despite similarity in the primary structure, the extracellular domains of NCAD and ECAD have different intrinsic stability, dimerization affinity and kinetics of disassembly. To investigate the origin of these differences, we are characterizing the modular domains individually. Here, we report studies of NCAD2, EC2 of NCAD. This domain is important for calcium binding and is the physical linkage between the dimerization interface in EC1 and the membrane proximal modular domains. Thermal-denaturation studies show that NCAD2 is less stable than ECAD2 and less influenced by the adjoining 7-residue, N- and C-terminal linker segments. In addition the NCAD2 constructs are less influenced by added salt. This difference is likely due to variation in the overall number and distribution of charges on these anionic proteins. Our studies indicate that despite their sequence similarity and apparently passive role in adhesive dimer formation, EC2 of E- and N-cadherins are distinctly different and may contribute to the differences in energetics and kinetics of dimerization.
AB - Neural- (NCAD) and epithelial- (ECAD) cadherin are calcium-dependent cell-adhesive molecules, and are localized at excitatory and inhibitory synapses respectively. They play an important role in synaptogenesis, synapse maintenance and plasticity. The extracellular region plays a critical role in cadherin-mediated cell adhesion, and has five tandemly repeated ectodomains (EC1-EC5). Calcium binding is required for dimer formation between first two N-terminal domains (EC1-EC2). Despite similarity in the primary structure, the extracellular domains of NCAD and ECAD have different intrinsic stability, dimerization affinity and kinetics of disassembly. To investigate the origin of these differences, we are characterizing the modular domains individually. Here, we report studies of NCAD2, EC2 of NCAD. This domain is important for calcium binding and is the physical linkage between the dimerization interface in EC1 and the membrane proximal modular domains. Thermal-denaturation studies show that NCAD2 is less stable than ECAD2 and less influenced by the adjoining 7-residue, N- and C-terminal linker segments. In addition the NCAD2 constructs are less influenced by added salt. This difference is likely due to variation in the overall number and distribution of charges on these anionic proteins. Our studies indicate that despite their sequence similarity and apparently passive role in adhesive dimer formation, EC2 of E- and N-cadherins are distinctly different and may contribute to the differences in energetics and kinetics of dimerization.
KW - Circular dichroism
KW - Electrostatic repulsion
KW - Thermal denaturation
UR - http://www.scopus.com/inward/record.url?scp=84860418445&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84860418445&partnerID=8YFLogxK
U2 - 10.1016/j.bbapap.2011.08.002
DO - 10.1016/j.bbapap.2011.08.002
M3 - Article
C2 - 21843662
AN - SCOPUS:84860418445
SN - 1570-9639
VL - 1814
SP - 1841
EP - 1845
JO - Biochimica et Biophysica Acta - Proteins and Proteomics
JF - Biochimica et Biophysica Acta - Proteins and Proteomics
IS - 12
ER -