Front Matter

94 5 Molecular Basis of Specificity and Stereoselectivity of Microbial Lipases

Table 2.Stereopreferences of lipases fromRhizopusandRhizomucor, andRhizopuslipase mutants
L258X (X¼A, S, F); stereopreferences are predicted fromUO3–C3and compared to experimentally
determined stereopreferences and stereoselectivities (enantiomeric excess, ee, and enantioselectivity,
E) of hydrolysis. (From Scheib et al., 1999.)

ROL UO3–C3( 8 ) Predicted
stereopreference

Experimentally

determined

stereopreference

ee^1 (%) E^2

Wild-type

Ether substrate 164 sn-1 sn-1 61 (2) 4
Ester substrate 170 sn-1 sn-1 19 (5) 1
Amide substrate 117 sn-3 sn-3 63 (6) 5
Phenyl substrate 118 sn-3 sn-3 77 (3) 8

L258A
Ether substrate n.d. n.d. sn-1 50 (5) 3
Ester substrate 157 sn-1 sn-1 16 (4) 1
Amide substrate 127 sn-3 sn-3 52 (4) 3
Phenyl substrate 170 sn-1 sn-1 68 (5) 5

L258S
Ether substrate n.d. n.d. sn-1 65 (4) 5
Ester substrate 165 sn-1 sn-1 14 (3) 1
Amide substrate 143 sn-3 sn-3 60 (3) 4
Phenyl substrate 164 sn-1 sn-1 53 (2) 3

L258F
Ether substrate n.d. n.d. sn-1 63 (5) 5
Ester substrate 155 sn-1 sn-1 23 (3) 2
Amide substrate 110 sn-3 sn-3 86 (5) 14
Phenyl substrate 96 sn-3 sn-3 91 (2) 22

RML UO3–C3( 8 ) Predicted
stereopreference

Experimentally

determined

stereopreference

ee^1 (%) E^2

Ether substrate 163 sn-1 sn-1 69 (4) 6
Ester substrate 169 sn-1 sn-1 73 (3) 7
Amid substrate 166 sn-1 sn-1 56 (2) 4
Phenyl substrate 173 sn-1 sn-1 68 (2) 6

(^1) ee¼½AŠ½BŠ
½AŠþ½BŠ
^100 ;if½AŠ>½BŠðn¼^12 Þ
(^2) E¼lnð^1 cð^1 þeePÞÞ
lnð 1 cð 1 eePÞÞ, if conversion c<10 %
n.d.: not determined.