Table 1.

Fit Parameters for the Allosteric Response caused by Different Amino Acid Analogues

Fit Parameters from Equation 2			Fit Parameters from Equation 3
	Allosteric Response
Commercial Name			Commercial Name
	Kix (mM)	Qax		Kix (mM)
L-Ala	0.33±0.01	0.100±0.001
L-Phe	3.9±0.3	0.39±0.01
		Carboxyl modifications
L-alanine methyl esterb	1.90±0.05	0.120±0.002	Ethanolamineb	50±20
			Ethylamineb,c	40±10
			Isopropylamineb,c	25±2
			L-alaninolb,c	25±1
			Butylamineb,c	—a
		Amino modifications
N-methyl-L-alab	1.1±0.2	0.16±0.01	Propionic Acidb,c	—a
L-Pro	1.40±0.04	0.063±0.001	N-formyl-L-alab,c	—a
			N-acetyl-L-alab,c	—a
		Chiral carbon modifications
D-alanineb	10±2	0.37±0.02	D-phenylalanineb	—a
2-aminoisobutyric acidb	11±2	0.16±0.01	S(+)-2-amino-2-methyl-3- phenyl-propionic acidb	—a
		Side Chain modifications
Glyb	23±2	0.26±0.01	L-homoserine	10±4
L-Cys	0.101±0.003	0.124±0.002	L-Ilee	31±8
L-Ser	4.6±0.4	0.24±0.01	L-norvaline	29±3
L-(+)-2,3-diaminopropionic acid	8±3	0.15±0.05	L-Asn	—a
L-(+)-2-aminobutyric acid (2AB)	0.43±0.02	0.05±0.01	L-Asp	—a
L-Val	7.6±0.4	0.090±0.004	L-Leu	—a
L-Thr	19.6±0.7	0.160±0.003	L-Glu	—a
L-Met	21±2	0.35±0.01	L-norleucine	—a
O-methyl-L-tyr	3.8±0.6	0.20±0.04	2-aminoheptanoic acid	—a
			2-aminocaprylic acid	—a
			L-His	—a
			L-Arg	—a
			L-Lys	—a
			3-cyclohexyl-L-alanine	—a
			(S)-(+)-2-phenylglycine	—a
			4-nitro-L-phenylalanine	—a
			L-homophenylalanine	—a
			L-Tyr	—a
			L-Trp	—a

^aK_a-PEP was not responsive to the amino acid analogue within the working concentration defined in Materials and Methods.

^bCorrected using H476L as described in supporting information

^cBinding tested by competition with Ala binding. When no K_ix value is listed, no competitive binding was detected.