Table 4. The predicted mutation effect on the protein structure stability of the bovine APP:c.569C>T, Ala199Val.

Folding Structure	Mutation site	Mutation energy kcal/mol †	Effect‡	van der Waals	Electricity	Entropy
primary	B-chain	0.46	neutral	0.34	0.27	0.19
	C-chain	-0.36	neutral	-0.92	0.23	-0.01
	D-chain	0.40	neutral	0.26	0.23	0.19
secondary	B, C-chain	-0.59	stabilizing	-2.85	0.84	0.51
	C, D-chain	-0.74	stabilizing	-2.67	0.88	0.19
	B, D-chain	0.52	destabilizing	-1.70	1.82	0.57
tertiary	B, C, D-chain	-1.80	stabilizing	-5.35	0.90	0.53

^† Differences between the folding free energy of mutated structure and wild-type protein. Sum of empirically weighted van der Waals force, electricity, entropy, and a non-polar surface dependent contribution (very small, not shown).

^‡ A mutation effect was defined as neutral if the mutation energy was between -0.5 to 0.5 kcal/mol, stabilizing if the mutation energy was less than -0.5kcal/mol, and destabilizing if the mutation energies was greater than 0.5 kcal/mol.