五八个必需氨基酸 (CH3)CHCHONH)COOH (CH3)CHCHCHNH2)COOH 缬氨酸Val 亮氨酸Leu CHsCHCHNH)COOH CH3CHCHNH2)COOH CH3 OH 异亮氨酸e 苏氨酸Thr CH5CH2CH(NH2)COOH CH3S(CH2)CH(NH2)COOH 苯丙氨酸Phe 蛋氨酸Met CH2CH(NH2)COOH HN(CH2)CH(NH)COOH 赖氨酸Lys 色氨酸Trp
五 八个必需氨基酸 (CH3) 2 CHCH(NH2)COOH 缬氨酸 Val (CH3) 2 CHCH2 CH(NH2)COOH 亮氨酸Leu C2 H5 CHCH(NH2)COOH CH3 异亮氨酸Ile C6H5 CH2 CH(NH2)COOH 苯丙氨酸Phe CH3 CHCH(NH2)COOH OH 苏氨酸Thr CH3 S(CH2) 2 CH(NH2)COOH 蛋氨酸Met H2 N(CH2) 4 CH(NH2)COOH 赖氨酸Lys CH2CH(NH2)COOH N H 色氨酸Trp
C00 C00 C00 *H3N-H +H3N-H *H3N-H H CH3 CH(CH3)2 Glycine(Gly) Alanine (Ala) Valine (Val) 甘氨酸 丙氨酸 缬氨酸 coO C00 C00 *H3N-H +H3N-H 肽 CH2 CH(CH3) +H2N CH(CH3)2 CH2CH3 骨架 Leucine (Leu) Isoleucine (Ile) 化 Proline (Pro) 亮氨酸 异亮氨酸 脯氨酸
C00 COO coO *H3N-H +H3N-H *H3N-H CH2 CH2 CH2 OH Phenylalanine (Phe) Tyrosine(Tyr) Tryptophan (Try) 苯丙氨酸 酪氨酸 色氨酸
coo coo coo +H3N-H +H3N- H +H3N-H CH2OH CHOH CH3 CH2SH Serine(Ser) Threonine(Thr) Cysteine(Cys) 丝氨酸 苏氨酸 半胱氨酸 coo c00 cOO +H3N-H +H3N- 一H *H3N-H CH2 CH2 CH2 CH2SCH3 CONH2 CH2 CONH2 Methionine (Met) Asparagine (Asn) Glutamine(GIn) 甲硫氨酸（蛋氨酸) 门冬酰胺 谷氨酰胺
C00 coo +H3N- H *HgN-H CH2 CH2 coo CH2 c00 Aspartate (Asp) Glutamate(Glu) 门冬氨酸 谷氨酸