An artificial polypeptide can be used in a treatment for Huntington's disease. The inventive polypeptide sequence is capable of interacting with mutant huntingtin so as to inhibit interactions between mutant huntingtin or a fragment of mutant huntingtin and calmodulin. The inventive polypeptide sequence can be a portion of calmodulin described herein or an analog or derivative thereof that binds with the polyglutamate portion of a mutant huntingtin protein. For example, polypeptide sequence can include a sequence of KDTDSEEEIREAFRVFDKDGNGYISAAELRHVMTNLGEKLTDEEV (SEQ ID NO: 1) or a portion thereof analog thereof or derivative thereof.