Purification and properties of glycolate oxidase from plants with different photosynthetic pathways: Distinctness of C4 enzyme from that of a C3 species and a C3–C4 intermediate

Abstract

Glycolate oxidase (GO; EC 1.1.3.1) was purified from the leaves of three plant species:Amaranthus hypochondriacus L.(NAD-ME type C4 dicot),Pisum sativum L. (C3 species) andParthenium hysterophorus L. (C3-C4. intermediate). A flavin moiety was present in the enzyme from all the three species. The enzyme from the C4 plant had a low specific activity, exhibited lower KM for glycolate, and required a lower pH for maximal activity, compared to the C3 enzyme. The enzyme from the C4 species oxidized glyoxylate at <10% of the rate with glycolate, while the GO from the C3 plant oxidized glyoxylate at a rate of about 35 to 40% of that with glycolate. The sensitivity of GO from C4 plant to α-hydroxypyridinemethane sulfonate, 2-hydroxy-3-butynoate and other inhibitors was less than that of the enzyme from C3 source. The properties of GO fromParthenium hysterophorus, were similar to those of the enzyme fromPisum sativum. The characteristics of glycolate oxidase from leaves of a C4 plant,Amaranthus hypochondriacus are different from those of the C3 species or the C3-C4 intermediate.

The role of photorespiration in redox and energy balance of photosynthetic plant cells: A study with a barley mutant deficient in glycine decarboxylase

“…To remove glyoxylate, a number of alternative reactions could be of importance. Glycolate oxidase can readily oxidize glyoxylate to oxalate with an appreciable rate (Igamberdiev et al 1988; Devi et al 1996) and this enzyme activity was also found to increase in the mutant (Table 2). Formate can be synthesized in peroxisomes by the direct oxidation of glyoxylate in the presence of hydrogen peroxide (Amory and Cresswell 1986).…”

Some structural properties of plant serine:glyoxylate aminotransferase?

“…Earlier we demonstrated that differences in pH optimum, thermal stability and kinetic constants also contributed to the differences observed (Truszkiewicz & Paszkowski, 2004). Glycolate oxidase -an important photorespiratory enzyme from a C 4 plant (Amaranthus hypochondriacus)-exhibited distinct kinetic properties as compared to the same enzyme from a C 3 plant (Pisum sativum) (Devi et al, 1996). Here we present the results of studies on the structure of SGAT from maize and wheat by means of molecular sieving on Zorbax SE-250 column and Millipore centrifugal filters.…”

Experimental Evidence for a Hydride Transfer Mechanism in Plant Glycolate Oxidase Catalysis

“…Interestingly, previous studies have shown differences between the kinetic parameters of GOXs from C 3 and C 4 plant species. GOX from C 4 species appear to have a lower K m for glycolate (10 M for Amaranthus hypochondriacus and 23 and 65 M for Zea mays guard cells and mesophyll cells, respectively) compared with C 3 species (330 M for Cucurbita pepo cotyledons, 300 M for Pisum sativum, 1 mM for S. oleracea, and 1.9 mM for Arabidopsis thaliana GOX2) (13)(14)(15)(16). These obser-FIGURE 1.…”