Geiger R, Sandow J, Kastin A J
Hoppe Seylers Z Physiol Chem. 1977 Nov;358(11):1475-81. doi: 10.1515/bchm2.1977.358.2.1475.
[Ser11]alpha-melanotropin has been prepared and its melanotropic activity compared with that of alpha-melanotropin and several known analogues. Full activity does not depend on the positive charge of 11-lysine in alpha-melanotropin but on the hydrophilic character of the amino group or a corresponding residue. A shift, or even more, a loss of such a group decreases the melanotropic activity.