Honors Theses
Date of Award
2007
Document Type
Undergraduate Thesis
Department
Chemistry and Biochemistry
First Advisor
Susan Pedigo
Relational Format
Dissertation/Thesis
Abstract
Neural cadherin is a member of a family of calcium binding cell adhesion molecules. These cell surface proteins mediate intercellular adhesion through association of protomers on the same cell surface to form lateral interactions, and juxtaposed cells then undergo adhesive interaction. This action occurs by ordered calcium dependent associations mediated through the five extracellular N-terminus β-barrel domains. While the critical function and structure of classic cadherin is well established, the energetic mechanism of adhesion is still unclear. This study includes experiments into the purification and stability of Domain 2 in neural cadherin with the motivation that Domain 2 is a representative domain for this family of proteins. The definition of a domain boundary is somewhat arbitrary, and hence it was important to examine the effect of the adjoining linker regions that connect Domain 2 to the adjacent domains. The studies presented here employ purification and energetic analysis of two constructs, the neural cadherin Domain 2 (NCAD2) and the domain with both linkers at the N- and C-termini (L1-NCAD2-L2). Temperature denaturation experiments were performed on these protein segments to gain insight on the effect of linkers on the core domain. Several trends between Domain 2 of neural and epithelial cadherin are evident from the resulting data and provide a paradigm of characteristics for defining Domain 2 in the classical cadherin family. Like ECAD2, the linker segments destabilize the core domain in the absence of calcium, but the destabilization of L1-NCAD2-L2 can be fully reversed by the addition of calcium. Sodium chloride steadily increases the stability of both constructs, indicating that the destabilization of the core domain in the presence of linkers is due to the electrostatic repulsion between those additional residues. Thus, the context of Domain 2 of classical cadherins within the whole protein affects its thermodynamic characteristics.
Recommended Citation
Mccool, John Kyle, "Stability Studies of Domain 2 of Neural Cadherin" (2007). Honors Theses. 2235.
https://egrove.olemiss.edu/hon_thesis/2235
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