Table 2.

Effect of mutations in the amino acid sequence of human CYP1A1 on the kinetic parameters of this enzyme.

Amino acid	Position	Amino acid type	Mutation	Amino acid type	Effect	Reference
Gly	45 loop A′	Nonpolar, aliphatic	Asp	Negatively charged	K m and V max⁡ are decreased by 42.9% and 75.1%, respectively	[75]
Ala	62 helix A	Nonpolar, aliphatic	Pro	Nonpolar, aliphatic	K m is increased by 84% and V max⁡ is decreased by 21%	[76]
Ser	116 helix B′	Polar, uncharged	Ala	Nonpolar, aliphatic	K m and V max⁡ do not change	[77]
Ser	122 loop B′-C	Polar, uncharged	Thr	Polar, uncharged	Activity is increased by 25%	[78]
			Ala	Nonpolar, aliphatic	K m and V max⁡ are increased by 74% and 2-fold, respectively	[79]
Phe	123 loop B′-C	Aromatic	Ala	Nonpolar, aliphatic	Without activity. K m is increased by 12.8-fold and V max⁡ is decreased by 42.5%	[77, 79]
Glu	161 helix D	Negatively charged	Lys	Positively charged	K m is decreased by 39% and V max⁡ does not change	[77]
Glu	166 helix D	Negatively charged	Gln	Nonpolar, aliphatic	K m and V max⁡ are increased by 3.7-fold and 24%, respectively	[77]
Val	191 helix E	Nonpolar, aliphatic	Met	Polar, uncharged	K m and V max⁡ do not change	[77]
Asn	221 helix F	Nonpolar, aliphatic	Thr	Polar, uncharged	Activity is decreased to 28%	[78]
Phe	224 helix F	Aromatic	Ala	Nonpolar, aliphatic	V max⁡ and K m are decreased by 11.4-fold and 75%, respectively	[79]
Gly	225 helix F	Nonpolar, aliphatic	Val	Nonpolar, aliphatic	Activity is decreased to 19%	[78]
Val	228 helix F	Nonpolar, aliphatic	Thr	Polar, uncharged	K m and V max⁡ do not change	[77]
Glu	256 helix G	Negatively charged	Lys	Positively charged	K m is decreased by 70% and V max⁡ does not change	[77]
Tyr	259 helix G	Aromatic	Phe	Aromatic	K m is increased by 2.7-fold and V max⁡ does not change	[77]
Asn	309 helix H	Nonpolar, aliphatic	Thr	Polar, uncharged	K m and V max⁡ do not change	[77]
Leu	312 helix I	Nonpolar, aliphatic	Asn	Nonpolar, aliphatic	Activity is decreased to 42%	[78]
			Phe	Aromatic	K m is increased by 89% and V max⁡ does not change	[77]
Asp	313 helix I	Negatively charged	Ala	Nonpolar, aliphatic	K m and V max⁡ are increased by 21-fold and 28%, respectively	[77]
			Asn	Nonpolar, aliphatic	K m is increased by 24.5-fold and V max⁡ is decreased by 37.5%	[77]
Gly	316 helix I	Nonpolar, aliphatic	Val	Nonpolar, aliphatic	K m is increased by 17-fold and V max⁡ is decreased by 30%	[77]
Ala	317 helix I	Nonpolar, aliphatic	Tyr	Aromatic	Without activity	[79]
			Gly	Nonpolar, aliphatic	K m is increased by 30-fold and V max⁡ is decreased by 25%	[77]
Asp	320 helix I	Negatively charged	Ala	Nonpolar, aliphatic	K m is increased by 2.7-fold and V max⁡ is decreased by 35%	[77]
Thr	321 helix I	Polar, uncharged	Gly	Nonpolar, aliphatic	K m is increased by 30% and V max⁡ is decreased by 70%	[79]
			Pro	Nonpolar, aliphatic	K m is increased by 6.2-fold and V max⁡ does not change	[77]
			Ser	Polar, uncharged	K m and V max⁡ are increased by 7.6-fold and 2-fold, respectively	[77]
Val	322 helix I	Nonpolar, aliphatic	Ala	Nonpolar, aliphatic	K m is increased by 67% and V max⁡ does not change	[77]
Val	382 helix K/ loop β1–4	Nonpolar, aliphatic	Ala	Nonpolar, aliphatic	Activity is decreased to 66%	[78]
			Leu	Nonpolar, aliphatic	Activity is decreased to 7%	[78]
Ile	386 helix K/ loop β1–4	Nonpolar, aliphatic	Gly	Nonpolar, aliphatic	Without activity	[79]
			Val	Nonpolar, aliphatic	K m and V max⁡ are increased by 87% and 58%, respectively	[77]
Ile	458 helix L	Nonpolar, aliphatic	Pro	Nonpolar, aliphatic	K m is increased by 44% and V max⁡ does not change	[77]
			Val	Nonpolar, aliphatic	K m and V max⁡ are decreased by 55% and 21%, respectively	[77]
Thr	497 loop β4	Polar, uncharged	Ser	Polar, uncharged	K m is increased by 3-fold and V max⁡ does not change	[77]