TY - JOUR
T1 - Isolation and characterization of a cDNA clone from Lolium temulentum L. encoding for a sucrose hydrolytic enzyme which shows alkaline/neutral invertase activity
AU - Gallagher, Joseph
AU - Pollock, Christopher
PY - 1998/5
Y1 - 1998/5
N2 - A novel cDNA clone, functionally expressed in E. coli, was isolated from a L. temulentum L. cDNA library. The expressed protein hydrolysed sucrose with an apparent Km of approximately 18 mM, and produced equi-molar concentrations of glucose and fructose. Optimum activity was observed at pH 7–7.5; there was little or no activity at pH 5.5. The expressed protein did not hydrolyse raffinose, stachyose or maltose. The activity of the expressed protein was inhibited by fructose (50% at 15 mM) and TRIS (50% at 2.5 mM), but was not affected by MgCl2, CaCl2 or MnCl2. These findings suggest that this cDNA clone encodes for an alkaline/neutral invertase. Sequence analysis revealed little homology with published sequences for acid invertase, however the invertase motif (NDPN) identified in other invertases was present. Expression studies show that the gene encoding for this enzyme is not regulated by sucrose accumulation in leaf tissue
AB - A novel cDNA clone, functionally expressed in E. coli, was isolated from a L. temulentum L. cDNA library. The expressed protein hydrolysed sucrose with an apparent Km of approximately 18 mM, and produced equi-molar concentrations of glucose and fructose. Optimum activity was observed at pH 7–7.5; there was little or no activity at pH 5.5. The expressed protein did not hydrolyse raffinose, stachyose or maltose. The activity of the expressed protein was inhibited by fructose (50% at 15 mM) and TRIS (50% at 2.5 mM), but was not affected by MgCl2, CaCl2 or MnCl2. These findings suggest that this cDNA clone encodes for an alkaline/neutral invertase. Sequence analysis revealed little homology with published sequences for acid invertase, however the invertase motif (NDPN) identified in other invertases was present. Expression studies show that the gene encoding for this enzyme is not regulated by sucrose accumulation in leaf tissue
KW - cDNA
KW - Lolium temulentum L
KW - sucrose hydrolysis
KW - invertase activity
UR - http://hdl.handle.net/2160/43352
U2 - 10.1093/jxb/49.322.789
DO - 10.1093/jxb/49.322.789
M3 - Article
SN - 0022-0957
VL - 49
SP - 789
EP - 795
JO - Journal of Experimental Botany
JF - Journal of Experimental Botany
IS - 322
ER -