isoelectric point help

[ginny08]

I need help w/ a question: Insulin protein has 2 polypeptides A and B. Human and duck insulins have the same sequence except for six below. Is the pI of human insulin higher or lower than duck insulin?

 

AA seq. A8 A9 A10 B1 B2 B27

Human Thr Ser Ile Phe Val Thr

Duck Glu Asn Pro Ala Ala Ser

[CharonY]

Well, check the properties of the respective amino acids (into what category do they fall, respectively) in each organism. This should give you the right idea.