中山大学：《有机化学》课程教学资源（课件讲稿）第十九章 氨基酸、肽和蛋白质 Amino Acids, Peptides and Protein

氨基酸( Amino acids) 2)20 standard amino acids 2. Aromatic R groups 3) cOo COo COo HaN 3 H HaNH CH CH 2 2 CH 2 OH Phenylalanine(Phe) yrosine(Tyr) Tryptophan(Try) 苯丙氨酸 酪氨酸 色氨酸 UⅤ特征吸收:入=280nm

一、氨基酸 (Amino Acids) （二）20 standard amino acids +H3N COO￾H CH2 +H3N COO￾H CH2 +H3N COO￾H CH2 Phenylalanine (Phe) Tyrosine (Tyr) Tryptophan (Try) 苯丙氨酸 酪氨酸 色氨酸 2. Aromatic R groups (3) N H OH UV 特征吸收：λ = 280 nm

E 20 standard amino acids 3. Polar, uncharged r groups(6) CoO COo COo H3N-H N—H CH,OH CHOH CH?SH CH Serine(ser) Threonine(thr Cysteine(Cys) 丝氨酸 苏氨酸 半胱氨酸 COO COO COO H 3 N H 3 CH 2 CH CH 2 CH2SCH3 CONH 2 CH 2 CONH 2 Methionine met) Asparagine(Asn) Glutamine(Gin) 甲硫氨酸(蛋氨酸) 门冬酰胺 谷氨酰胺

（二）20 standard amino acids +H3N COO￾H CH2OH +H3N COO￾H CHOH +H3N COO￾H CH2SH +H3N COO￾H CH2 +H3N COO￾H CH2 CH2SCH3 CONH2 Serine (Ser) Threonine (Thr) Cysteine (Cys) Methionine (Met) Asparagine (Asn) Glutamine (Gln) 丝氨酸 苏氨酸 半胱氨酸 甲硫氨酸（蛋氨酸） 门冬酰胺 谷氨酰胺 3. Polar, uncharged R groups (6) CH3 +H3N COO￾H CH2 CH2 CONH2

Amino acids )20 standard amino acids 4. Negatively charged groups(2 COO COo 3 2 2 COO 2 COo Aspartate(Asp) Glutamate(Glu 门冬氨酸 谷氨酸 Acidic amino acids-containing two carboxylic groups

一、Amino Acids （二）20 standard amino acids Acidic amino acids——containing two carboxylic groups +H3N COO￾H CH2 COO￾Aspartate (Asp) Glutamate(Glu) 门冬氨酸 谷氨酸 +H3N COO￾H CH2 CH2 COO- 4. Negatively charged R groups (2)

)20 standard amino acids 5. Positively charged r groups 3) COo Coo H3N H HrN-H CH 2 CH COo 2 CH CH HaN H 2 2 CH 2 CH 2 HoC CH. NH imidazole NH guanidin C=NH2 NH HNS NH 2 ysine (lys Arginine (arg) Histidine 赖氨酸 精氨酸 组氨酸 Basic amino acids containing two amino groups

（二）20 standard amino acids Basic amino acids —— containing two amino groups +H3N COO￾H CH2 CH2 Lysine (Lys) Arginine (Arg) 赖氨酸 精氨酸 +H3N COO￾H CH2 CH2 CH2 5. Positively charged R groups (3) CH2 CH2 NH3+ NH C NH2 NH2+ +H3N COO￾H H2C HN guanidino NH imidazole Histidine 组氨酸

Histidine(酸碱催化中的重要氨基酸) COo COO HaN H 3 N H2-7 HNeNH THNA.NH -H COo COO HaN 13 K =6.00 H3N-TH HC. CH2 HN、AN N心NH

Histidine (酸碱催化中的重要氨基酸) COO H CH2 H3N COO H H2C H3N pKa=6.00 HN N N NH COO H H2C H3N HN NH+ COO H H2C H3N +HN NH H+ -H+