Lyase substrate specificity

Prasad R, Beard WA, Strauss PR, Wilson SH. Human DNA polymerase beta deoxyribose phosphate lyase. Substrate specificity and catalytic mechanism. J. Biol. Chem. 1998 273 15263-15270. Prasad R, Bebenek K, Hou E, Shock DD, Beard WA, Woodgate R, Kunkel TA, Wilson SH. Localization of the deoxyribose phosphate lyase active site in human DNA polymerase iota by controlled proteolysis. J. Biol. Chem. 2003 278 29649-29654. 

Shukla, A. K., and Schauer, R., 1986, Analysis of sialidase and N-acetylneuraminate pyruvate lyase substrate specificity by high-performance liquid chromatography. Anal. Biochem. 158 158-164. 

The mode of action and substrate specificity of all pectin lyases together with the endopolygalacturonases is currently one of the main topics of our research. 

Substrate specificity and mode of action. Previous information, which we had obtained from FORL crude culture filtrates, showed that the pectin lyase (characterized by an isoelectric point of 9.2) had a predominantly "endo" way of action. This fact has been confirmed with the purified protein it decreased the viscosity of reaction mixtures with pectin, but no increase in absorbance was detected in standard conditions. Moreover, the enzyme showed a great specificity for the substrate, as no activity was detected when the decrease in viscosity of pectate was tried. So, properties of the purified enzyme were studied by using pectin as substrate and following the decrease in viscosity of the reaction mixtures. 

S. Yu, T. Ahmad, L. Kenne, and M. Pedersen, a-1,4-Glucan lyase, a new class of starch glycogen degrading enzyme. 3. Substrate specificity, mode of action, and cleavage mechanism, BBA General Subjects, 1244 (1995) 1-9. 

Lrthreonine aldolase (L-threonine acetaldehyde-lyase) catalyzes the reversible condensation of acetaldehyde and glycine to form L-threonine. The enzyme has been shown to be an activity distinct from serine hydroxy-methyltransferase that also catalyzes the above reaction (85,86). The substrate specifically of the adolase has been demonstrated to be flexible with respect to the aldehyde involved. The enzyme has been shown to form phenylserine derivatives from substituted benzaldehydes and glycine (86). 

Fatty acid hydroperoxide lyase is one of the enzymes responsible for volatile Cft- and C9-aldehyde formation from linoleic and linolenic acid. This enzyme cleaves 9- and/or 13-hydroperoxides derived from linoleic and linolenic acid. The enzyme is distributed in a wide range of plant species in membrane bound forms both chloroplastic and non-chloroplastic. Three types of hydroperoxide lyases have been reported 9-hydroperoxide-specific, 13-hydroperoxide-specific and nonspecific. Other properties of the hydroperoxide lyase including substrate specificity and reaction mechanism are discussed in this review. 

Major products of the lipoxygenase reaction are 9- and 13-hydroperoxides of IV and V, VI, VII, VIII and IX. Hydroperoxide lyase utilizes the 9- and/or 13-hydroperoxides (VI, VII, VIII and IX). Based on substrate specificity, hydroperoxide lyase is classified into three types. The first type is 9-hydroperoxide-specific. 

Table I. Substrate Specificity of HPO Lyase Solubilized from Tea Chloroplast...

Fig. 3. Substrate specificity of heparin lyases. The arrows indicate the glucosaminidic linkages cleaved by the enzymes. Both configurations of the carboxylate group are shown when both IdoA and GlcA are compatible with lyase action. An unsubstituted hydroxyl group at C-3 of the GlcN residue toward the reducing end is a prerequisite for susceptibility to lyases II and III. Other groups essential for cleavage with the indicated enzyme are shown in bold type. (Adapted from Ref. 98.)...

Cystalysin bas a relatively broad substrate specificity. In addition to L-cysteine, cystalysin accommodates /3-cbloroalanine, cysteine metbyl ester, S -etbylcysteine, and xS-metbylcysteine as substrates for /3-elimination reactions. " In addition cystalysin exhibits a bigb catalytic versatility. It is a cyst(e)ine C—S lyase, catalyzes AlaR reaction, tbe /3-desullination of L-cysteine sulfmic acid and tbe /3-decarboxylation of L-aspartate and oxalacetate. a,/3-Elimination and racemization probably share the step leading to the quinonoid intermediate, and the same catalytic residues. ... 

Leishmania adenylosuccinate synthetase has a narrow substrate specificity but accepts several IMP analogs which include allopurinol ribonucleotide (34). The GMP reductase from L. donovani is quite different from the human GMP reductase (35) and IMP analogs are more potent inhibitors for it. Other leishmanial enzymes that have been investigated include IMP dehydrogenase (36), nucleoside hydrolase and phos-phorylase activities (37,38), adenosine kinase (39), nucleotidases (40) and the adenylosuccinate lyase (34). 

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