TY - JOUR
T1 - Purification and characterization of a guanosine diphosphatase activity from calf liver microsomal salt wash proteins
AU - Raychaudhuri, P.
AU - Ghosh, S.
AU - Maitra, U.
PY - 1985
Y1 - 1985
N2 - A potent guanosine diphosphatase activity that hydrolyzes GDP to 5'-GMP + P(i) has been isolated and purified from the salt wash proteins of calf liver microsomes. The purified enzyme, a monomeric protein of approximate M(r) 46,000, possesses nucleotide substrate specificity since, among the nucleoside diphosphates and triphosphates tested, only GDP and UDP are hydrolyzed by the enzyme. The relative affinity of the enzyme for GDP is, however, much higher than for UDP. The effect of the enzyme on the binary complex formed between eukaryotic initiation factor 2 (eIF-2) and GDP has also been investigated. The enzyme neither hydrolyzes GDP bound to eIF-2 nor catalyzes the exchange of eIF-2-bound GDP with GTP even in the presence of Met-tRNA(f). The enzyme, therefore, is presumably not involved in recycling of eIF-2 in eukaryotic polypeptide chain initiation reaction. The possible biological function of the enzyme in maintaining the cellular pool of GTP-GDP is discussed.
AB - A potent guanosine diphosphatase activity that hydrolyzes GDP to 5'-GMP + P(i) has been isolated and purified from the salt wash proteins of calf liver microsomes. The purified enzyme, a monomeric protein of approximate M(r) 46,000, possesses nucleotide substrate specificity since, among the nucleoside diphosphates and triphosphates tested, only GDP and UDP are hydrolyzed by the enzyme. The relative affinity of the enzyme for GDP is, however, much higher than for UDP. The effect of the enzyme on the binary complex formed between eukaryotic initiation factor 2 (eIF-2) and GDP has also been investigated. The enzyme neither hydrolyzes GDP bound to eIF-2 nor catalyzes the exchange of eIF-2-bound GDP with GTP even in the presence of Met-tRNA(f). The enzyme, therefore, is presumably not involved in recycling of eIF-2 in eukaryotic polypeptide chain initiation reaction. The possible biological function of the enzyme in maintaining the cellular pool of GTP-GDP is discussed.
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M3 - Article
C2 - 2989286
AN - SCOPUS:0022252944
VL - 260
SP - 8306
EP - 8311
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 14
ER -