Abstract
A true Brønsted analysis of proton transfer in an enzyme mechanism is made possible by the chemical rescue of an inactive mutant of aspartate aminotransferase, where the endogenous general base, Lys258, is replaced with Ala by site-directed mutagenesis. Catalytic activity is restored to this inactive mutant by exogenous amines. The eleven amines studied generate a Brønsted correlation with β of 0.4 for the transamination of cysteine suilfinate, when steric effects are included in the regression analysis. Localized mutagenesis thus allows the classical Brønsted analysis of transition-state structure to be applied to enzyme-catalyzed reactions.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1485-1488 |
| Number of pages | 4 |
| Journal | Science |
| Volume | 243 |
| Issue number | 4897 |
| State | Published - 1989 |
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Direct Brønsted analysis of the restoration of activity to a mutant enzyme by exogenous amines. / Toney, Michael D.; Kirsch, Jack F.
In: Science, Vol. 243, No. 4897, 1989, p. 1485-1488.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Direct Brønsted analysis of the restoration of activity to a mutant enzyme by exogenous amines
AU - Toney, Michael D.
AU - Kirsch, Jack F.
PY - 1989
Y1 - 1989
N2 - A true Brønsted analysis of proton transfer in an enzyme mechanism is made possible by the chemical rescue of an inactive mutant of aspartate aminotransferase, where the endogenous general base, Lys258, is replaced with Ala by site-directed mutagenesis. Catalytic activity is restored to this inactive mutant by exogenous amines. The eleven amines studied generate a Brønsted correlation with β of 0.4 for the transamination of cysteine suilfinate, when steric effects are included in the regression analysis. Localized mutagenesis thus allows the classical Brønsted analysis of transition-state structure to be applied to enzyme-catalyzed reactions.
AB - A true Brønsted analysis of proton transfer in an enzyme mechanism is made possible by the chemical rescue of an inactive mutant of aspartate aminotransferase, where the endogenous general base, Lys258, is replaced with Ala by site-directed mutagenesis. Catalytic activity is restored to this inactive mutant by exogenous amines. The eleven amines studied generate a Brønsted correlation with β of 0.4 for the transamination of cysteine suilfinate, when steric effects are included in the regression analysis. Localized mutagenesis thus allows the classical Brønsted analysis of transition-state structure to be applied to enzyme-catalyzed reactions.
UR - http://www.scopus.com/inward/record.url?scp=0024478059&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0024478059&partnerID=8YFLogxK
M3 - Article
C2 - 2538921
AN - SCOPUS:0024478059
VL - 243
SP - 1485
EP - 1488
JO - Science
JF - Science
SN - 0036-8075
IS - 4897
ER -