onr:"swepub:oai:DiVA.org:umu-44641"
Search: onr:"swepub:oai:DiVA.org:umu-44641" > Regulation of the s...
- 1 of 1
- Previous record
- Next record
- To hitlist
| Fältnamn | Indikatorer | Metadata |
|---|---|---|
| 000 | 03533naa a2200301 4500 | |
| 001 | oai:DiVA.org:umu-44641 | |
| 003 | SwePub | |
| 008 | 110609s1996 | |||||||||||000 ||eng| | |
| 024 | 7 | a https://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-446412 URI |
| 040 | a (SwePub)umu | |
| 041 | a engb eng | |
| 042 | 9 SwePub | |
| 072 | 7 | a ref2 swepub-contenttype |
| 072 | 7 | a art2 swepub-publicationtype |
| 100 | 1 | a Kromer, S4 aut |
| 245 | 1 0 | a Regulation of the supply of cytosolic oxaloacetate for mitochondrial metabolism via phospho enolpyruvate carboxylase in barley leaf protoplasts .1. The effect of covalent modification on PEPC activity, pH response, and kinetic properties |
| 264 | 1 | c 1996 |
| 338 | a print2 rdacarrier | |
| 520 | a The regulation of the supply of oxaloacetate (OAA) for mitochondrial metabolism via phosphoenolpyruvate carboxylase (PEPC) by covalent modification is studied in barley (Hordeum vulgare L.) leaf protoplasts in light or darkness as well as under photorespiratory or non-photorespiratory conditions. Extracts for studies on in vivo PEPC phosphorylation were prepared from barley leaf protoplasts by rapid filtration, fractionating the cell within less than 1 s. Measurements of in vitro PEPC activity were performed on samples quickly frozen in liquid nitrogen to break the cell and stop metabolism and thus preserve the in vivo activation state. The relative PEPC phosphorylation state increased upon illumination and decreased upon redarkening under photorespiratory and non-photorespiratory conditions. PEPC activity measured in the presence of malate (3 mM) under photorespiratory conditions showed the same response indicating that a light-induced increase in PEPC activity and decrease in malate sensitivity is caused by an increased phosphorylation level of the PEPC protein. PEPC activity was pH dependent. At the physiological cytosolic pH, activity was suboptimal, but most sensitive towards malate inhibition and glucose 6-phosphate stimulation. The presence of malate increased the sensitivity of PEPC activity towards pH changes. The response of PEPC activity to changing pH was not affected by changes in the activation state of the enzyme. The K-m (phosphoenolpyruvate, PEP) is about 1 mM. Upon illumination the K-m (PEP) decrease significantly. V-max was unaffected by the light treatment. The presence of physiological concentrations of glucose 6-phosphate decreased K-m (PEP) 5- to 10-fold and increased V-max by about 35%. The effect of glucose 6-phosphate was strongest (up to 7-fold) at subsaturating PEP concentrations stimulating PEPC activity to nearly maximal rates. The results show that an increase in PEPC phosphorylation state causes an increase in PEPC activity as well as in substrate affinity leading to an increased production of OAA in the light. | |
| 653 | a cytosolic oxaloacetate | |
| 653 | a phosphoenolpyruvate | |
| 653 | a protoplast | |
| 653 | a (H-vulgare L) | |
| 700 | 1 | a Gardeström, Per,d 1950-u Umeå universitet,Institutionen för fysiologisk botanik,Umeå Plant Science Centre (UPSC)4 aut0 (Swepub:umu)pega0001 |
| 700 | 1 | a Samuelsson, Göran,d 1951-u Umeå universitet,Institutionen för fysiologisk botanik,Umeå Plant Science Centre (UPSC)4 aut0 (Swepub:umu)gosa0002 |
| 710 | 2 | a Umeå universitetb Institutionen för fysiologisk botanik4 org |
| 773 | 0 | t Biochimica et Biophysica Acta - General Subjectsg 1289:3, s. 343-350q 1289:3<343-350x 0304-4165x 1872-8006 |
| 856 | 4 8 | u https://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-44641 |
Find in a library
- Biochimica et Biophysica Acta - General Subjects (Search for host publication in LIBRIS)
To the university's database
- 1 of 1
- Previous record
- Next record
- To hitlist
Find more in SwePub
- By the author/editor
- Kromer, S
- Gardeström, Per, ...
- Samuelsson, Göra ...
- Articles in the publication
- Biochimica et Bi ...
- By the university
- Umeå University
Search outside SwePub
- Extend your search to:
- Google Book Search
- Google Scholar
Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.
- Copyright © LIBRIS - National Library Systems
- LIBRIS.kb.se
