- Eliminating positively charged lysine epsilon-NH3+ groups on the surface of carbonic anhydrase has no significant influence on its folding from sodium dodecyl sulfate. Gudiksen, K.L., Gitlin, I., Yang, J., Urbach, A.R., Moustakas, D.T., Whitesides, G.M. J. Am. Chem. Soc. (2005)