Digital Repository

Amino acid transport : the special case of a H/L-glutamate cotransport system in Asparagus sprengeri mesophyll cells /

DSpace/Manakin Repository

Show simple item record

dc.contributor.author McCutcheon, Steve L. en_US
dc.date.accessioned 2009-06-09T18:16:29Z
dc.date.available 2009-06-09T18:16:29Z
dc.date.issued 1987-06-09T18:16:29Z
dc.identifier.uri http://hdl.handle.net/10464/1571
dc.description.abstract The addition of L-Glutamate (L-GLU) and L-Hethionine ~ulfoximine (L-HSO) to mechanically isolated. photosynthetically competent, Asparagus sprengeri mesophyll cells ~u~pended in 1mM CaS04 cau~ed an immediate transient alkalinization of the cell su~pension medium in both the light and dark. The alkalinization response was specific and stereospecific as none of the L-isomers of the other 19 protein amino acids tested or D-GLU gave this response. Uptake of 14C-L-GLU was stimulated by the light. The addition of non-radioactive L-GLU. or L-GLU analogs together with 14C-L-GLU showed that only L-GLU and L-HSO stimulated alkalinization whilst inhibiting the uptake of 14C-L-GLU. Both the L-GLU dependent alkalinization and the upt~ke of 14C-L-GLU were stimulated when the external pH was decreased from 6.5 to 5.5. Increasing external K+ concentrations inhibited the uptake of 14C-L-GLU. Fusicoccin (FC) stimulated uptake. The L-GLU dependent alkalinization re~ponse exhibited monophasic saturation kinetics while the uptake of 14C-L-GLU exhibited biphasic saturation kinetics. In addition to a saturable component. the uptake kinetics also showed a linear component of uptake. Addition of L-GLU and L-MSO caused internal acidification of the cell as measured by a change in the distribution of 14C-DMO. There was no change in K+ efflux when L-GLU was added. A H+ to L-GLUinflux stoichiometry of 3:1 wa~ mea~ured at an external I.-GLU concentration of O.5mM and increased with increasing external 13 L-QLU concentration. Metabolism of L-GLU was detected manometrlcally by observing an increase in COa evolution upon the addition of L-QLU and by detection of i*C02 evolution upon the addition of »*C-L-GLU. »*C02 evolution was higher in the dark than in the light. The data are consistent with the operation of a H+/L-QLO cotransport system. The data also show that attempts to quantify the stoichlometry of the process were complicated by the metabolism of L-GLU. en_US
dc.language.iso eng en_US
dc.publisher Brock University en_US
dc.subject Amino acids. en_US
dc.subject Asparagus sprengeri. en_US
dc.subject Cells. en_US
dc.title Amino acid transport : the special case of a H/L-glutamate cotransport system in Asparagus sprengeri mesophyll cells / en_US
dc.type Electronic Thesis or Dissertation en_US
dc.degree.name M.Sc. Biological Sciences en_US
dc.degree.level Masters en_US
dc.contributor.department Department of Biological Sciences en_US
dc.degree.discipline Faculty of Mathematics and Science en_US


Files in this item

This item appears in the following Collection(s)

Show simple item record

Search The Repository


Browse

My Account

Statistics


About the Digital Repository