Biomaterial Database

Amino acid sequence at the citrate allosteric site of rabbit muscle phosphofructokinase. 1987

R G Kemp, and R W Fox, and S P Latshaw

Department of Biological Chemistry and Structure, University of Health Sciences, Chicago Medical School, Illinois 60064.

Previously, this laboratory has demonstrated [Colombo, G., & Kemp, R. G. (1976) Biochemistry 15, 1774-1780] that under appropriate conditions the citrate inhibitory binding site of rabbit skeletal muscle phosphofructokinase can be covalently modified by using pyridoxal phosphate and sodium borohydride. In the current study, phosphofructokinase was modified by [3H]pyridoxal phosphate and sodium borohydride with or without the addition of citrate to protect the ligand binding site. The modified proteins were digested with trypsin, and the peptides were separated by high-pressure liquid chromatography. A comparison of the tryptic chromatographic profiles showed that while the label was broadly distributed among nine peaks in the elution profile of the enzyme modified in the presence of the protective ligand, a single peptide contained 70% of the total radioactivity of the enzyme modified in the absence of citrate. This peptide was presumed to contain at least part of the citrate inhibitory site of the enzyme. The sequence of the peptide was determined and shown to match with positions 528-536 of phosphofructokinase with the modified residue being Lys-529. A comparison of the sequence with that of procaryotic phosphofructokinase indicated that a homologous residue in the enzyme from Bacillus stearothermophilis is critical to an allosteric site. A second peptide that was the most abundant labeled peptide in the digest of the enzyme modified in the presence of citrate was found to be identical with the second most abundant peptide of the digest from the unprotected enzyme. This peptide corresponded to residues 681-692 with the lysine at position 684 being the site of phosphopyridoxylation.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D010732	Phosphofructokinase-1	An allosteric enzyme that regulates glycolysis by catalyzing the transfer of a phosphate group from ATP to fructose-6-phosphate to yield fructose-1,6-bisphosphate. D-tagatose- 6-phosphate and sedoheptulose-7-phosphate also are acceptors. UTP, CTP, and ITP also are donors. In human phosphofructokinase-1, three types of subunits have been identified. They are PHOSPHOFRUCTOKINASE-1, MUSCLE TYPE; PHOSPHOFRUCTOKINASE-1, LIVER TYPE; and PHOSPHOFRUCTOKINASE-1, TYPE C; found in platelets, brain, and other tissues.	6-Phosphofructokinase,6-Phosphofructo-1-kinase,Fructose-6-P 1-Kinase,Fructose-6-phosphate 1-Phosphotransferase,6 Phosphofructokinase,Phosphofructokinase 1
D011732	Pyridoxal Phosphate	This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).	Pyridoxal 5-Phosphate,Pyridoxal-P,Phosphate, Pyridoxal,Pyridoxal 5 Phosphate,Pyridoxal P
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D002951	Citrates	Derivatives of CITRIC ACID.
D000495	Allosteric Site	A site on an enzyme which upon binding of a modulator, causes the enzyme to undergo a conformational change that may alter its catalytic or binding properties.	Allosteric Sites,Site, Allosteric,Sites, Allosteric
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014357	Trypsin	A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.	Tripcellim,Trypure,beta-Trypsin,beta Trypsin