上游充通大￥ SHANGHAI JIAO TONG UNIVERSITY 1.Proteins Are Built from a Repertoire of 20 Amino Acids (1)非极性氨基酸： R基为脂肪侧链（5)： H3 H2 +H3N H3N coo H3N +H3N H3N C00 CH3 +H3N C00- CH3 H H CH3 Alanine C00 HaN COO- +H3N- C00 (Ala,A) H H H Valine Leucine Isoleucine Methionine (Val.V) (Leu.Ll (lle-I1 (Met.M) 丙氨酸 缬氨酸 亮氨酸 异亮氨酸 甲硫氨酸1.Proteins Are Built from a Repertoire of 20 Amino Acids 丙氨酸 R基为脂肪侧链（5）： （1）非极性氨基酸： 缬氨酸 亮氨酸 异亮氨酸 甲硫氨酸