PMID- 1515468
OWN - NLM
STAT- MEDLINE
DCOM- 19921006
LR  - 20191021
IS  - 1043-1802 (Print)
IS  - 1043-1802 (Linking)
VI  - 3
IP  - 2
DP  - 1992 Mar-Apr
TI  - Photochemical cross-linking of guanosine 5'-triphosphate to phosphoenolpyruvate 
      carboxykinase (GTP).
PG  - 160-6
AB  - Mammalian phosphoenolpyruvate carboxykinase (PEPCK) specifically requires a 
      guanosine or inosine nucleotide as a substrate; however, the structural basis for 
      this nucleotide specificity is not yet known. Because affinity labels derived 
      from guanosine have not yielded a stable, modified peptide in quantities 
      sufficient for sequence analysis, we have investigated the utility of direct 
      photochemical cross-linking of GTP to PEPCK in order to identify the nucleotide 
      binding site. UV irradiation at a distance of 2 cm by a Mineralight lamp (330 
      microW/cm2) results in the attachment of [alpha-32P]GTP to PEPCK via a stable, 
      covalent linkage in a reaction that is dependent upon GTP concentration and 
      duration of irradiation. After 10 min of irradiation, more than 0.2 mol of 
      [alpha-32P] GTP is incorporated per mole of PEPCK; under these conditions the GTP 
      concentration required for half-maximal labeling is 69 microM. The substrates 
      phosphoenolpyruvate, ITP, and GDP provide protection against photolabeling, as do 
      Mn2+ and Mg2+. One major and one minor radioactive peptide derived from 
      proteolytic digests of photolabeled PEPCK have been isolated and identified. The 
      major modified peptide has been provisionally assigned to an acidic region near 
      the C-terminus, and the minor peptide has been identified as Ser462-Lys471.
FAU - Lewis, C T
AU  - Lewis CT
AD  - Department of Biochemistry, University of Tennessee, College of Medicine, Memphis 
      38163.
FAU - Seyer, J M
AU  - Seyer JM
FAU - Carlson, G M
AU  - Carlson GM
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Bioconjug Chem
JT  - Bioconjugate chemistry
JID - 9010319
RN  - 0 (Cross-Linking Reagents)
RN  - 132-06-9 (Inosine Triphosphate)
RN  - 146-91-8 (Guanosine Diphosphate)
RN  - 415SHH325A (Adenosine Monophosphate)
RN  - 86-01-1 (Guanosine Triphosphate)
RN  - EC 3.4.21.- (Serine Endopeptidases)
RN  - EC 3.4.21.19 (glutamyl endopeptidase)
RN  - EC 4.1.1.32 (Phosphoenolpyruvate Carboxykinase (GTP))
SB  - IM
MH  - Adenosine Monophosphate/chemistry
MH  - Amino Acid Sequence
MH  - Chromatography, High Pressure Liquid
MH  - Cross-Linking Reagents
MH  - Guanosine Diphosphate/chemistry
MH  - Guanosine Triphosphate/*chemistry
MH  - Inosine Triphosphate/chemistry
MH  - Molecular Sequence Data
MH  - Phosphoenolpyruvate Carboxykinase (GTP)/*chemistry
MH  - Serine Endopeptidases/metabolism
EDAT- 1992/03/01 00:00
MHDA- 1992/03/01 00:01
CRDT- 1992/03/01 00:00
PHST- 1992/03/01 00:00 [pubmed]
PHST- 1992/03/01 00:01 [medline]
PHST- 1992/03/01 00:00 [entrez]
AID - 10.1021/bc00014a011 [doi]
PST - ppublish
SO  - Bioconjug Chem. 1992 Mar-Apr;3(2):160-6. doi: 10.1021/bc00014a011.