Evolution of Enzymatic Activities in the Enolase Superfamily:  Identification of the General Acid Catalyst in theActive Site ofd-Glucarate Dehydratase fromEscherichia coli†,‡

Biochemistry ◽  
2001 ◽  
Vol 40 (34) ◽  
pp. 10054-10062 ◽  
Author(s):  
Andrew M. Gulick ◽  
Brian K. Hubbard ◽  
John A. Gerlt ◽  
Ivan Rayment
Keyword(s):  
Acid Catalyst ◽  
Enzymatic Activities ◽  
Fromescherichia Coli ◽  
General Acid ◽  
Enolase Superfamily

Does pyridoxal 5'-phosphate function in glycogen phosphorylase as an electrophilic or a general acid catalyst?

Biochemistry ◽  
1984 ◽  
Vol 23 (24) ◽  
pp. 5853-5861 ◽  
Author(s):  
Helmut W. Klein ◽  
Mie J. Im ◽  
Dieter Palm ◽  
Ernst J. M. Helmreich
Keyword(s):  
Glycogen Phosphorylase ◽  
Acid Catalyst ◽  
General Acid

Evolution of Enzymatic Activities in the Enolase Superfamily:  Structure of a Substrate-Liganded Complex of thel-Ala-d/l-Glu Epimerase fromBacillus subtilis†,‡

Biochemistry ◽  
2004 ◽  
Vol 43 (32) ◽  
pp. 10370-10378 ◽  
Author(s):  
Vadim A. Klenchin ◽  
Dawn M. Schmidt ◽  
John A. Gerlt ◽  
Ivan Rayment
Keyword(s):  
Enzymatic Activities ◽  
Enolase Superfamily

scholarly journals Arginine as a General Acid Catalyst in Serine Recombinase-mediated DNA Cleavage

2013 ◽  
Vol 288 (40) ◽  
pp. 29206-29214 ◽  
Author(s):  
Ross A. Keenholtz ◽  
Kent W. Mouw ◽  
Martin R. Boocock ◽  
Nan-Sheng Li ◽  
Joseph A. Piccirilli ◽  
...  
Keyword(s):  
Dna Cleavage ◽  
Acid Catalyst ◽  
Serine Recombinase ◽  
General Acid

The mechanism of the nonenzymatic iodination of tyrosine by molecular iodine

1988 ◽  
Vol 66 (9) ◽  
pp. 967-978 ◽  
Author(s):  
H. Brian Dunford ◽  
Adejare J. Adeniran
Keyword(s):  
Ph Dependence ◽  
Acid Catalyst ◽  
Order Rate Constant ◽  
Molecular Iodine ◽  
Base Catalysis ◽  
Slow Step ◽  
Rate Law ◽  
General Acid ◽  
Phenolic Group ◽  
Ph Range

Over the pH range 7–10, at very low buffer concentration, the nonenzymatic iodination of tyrosine obeys the rate law[Formula: see text]where kapp is the measured second order rate constant based upon the total initial concentrations of molecular iodine and tyrosine and K2 (units M) is the equilibrium constant for [Formula: see text]. The value of k′ is 3.5 × 10−8 M∙s−1. There are three plausible mechanisms that fit the experimental data. One, the simplest, is a concerted process in which hypoiodous acid attacks tyrosine with its phenolic group unionized. The other two involve the formation of an iodinated quinoid reactive intermediate species in a rapid pre-equilibrium between unionized tyrosine and either hypoiodous acid or molecular iodine. The pre-equilibrium, if it occurs, favors the initial reactants. It is followed by a slow step in which the quinoid is converted to mono-iodinated tyrosine. Positive deviations from the rate law for pH dependence indicate that some specific acid catalysis (H3O+) is occurring in the pH range 5–7. In the presence of sufficient buffer, general acid–base catalysis is observed with acetic acid acting as a general acid catalyst in the vicinity of pH 5 and carbonate acting as a general base at pH ~ 9.5. The nonenzymatic iodination of tyrosine occurs more rapidly as the pH is increased, in marked contrast to the peroxidase-catalyzed iodination, which has its optimum at low pH.

scholarly journals Evolution of Enzymatic Activities in the Enolase Superfamily: Galactarate Dehydratase III fromAgrobacterium tumefaciensC58

Biochemistry ◽  
2014 ◽  
Vol 53 (25) ◽  
pp. 4192-4203 ◽  
Author(s):  
Fiona P. Groninger-Poe ◽  
Jason T. Bouvier ◽  
Matthew W. Vetting ◽  
Chakrapani Kalyanaraman ◽  
Ritesh Kumar ◽  
...  
Keyword(s):  
Enzymatic Activities ◽  
Enolase Superfamily

Evolution of Enzymatic Activities in the Enolase Superfamily: N-Succinylamino Acid Racemase and a New Pathway for the Irreversible Conversion ofd- tol-Amino Acids†

Biochemistry ◽  
2006 ◽  
Vol 45 (14) ◽  
pp. 4455-4462 ◽  
Author(s):  
Ayano Sakai ◽  
Dao Feng Xiang ◽  
Chengfu Xu ◽  
Ling Song ◽  
Wen Shan Yew ◽  
...  
Keyword(s):  
Amino Acids ◽  
Enzymatic Activities ◽  
Enolase Superfamily
Sign in / Sign up

Export Citation Format

Share Document