Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.3 (RNase T1)
 1,228 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the cocrystal formed by 7-methylguanosine-5'-phosphate.phenylalanine.6H2O, the interactions between guanine and phenylalanine are similar to those observed in the complex of ribonuclease T1 with 2'-guanylic acids, and those of the two G-proteins, Elongation Factor-Tu and ras oncogene p21, with GDP. They are similar in the following three points: (a) guanine N(1)H and N(2)H donate cyclic N-H...O hydrogen bonds to the carboxylate group of phenylalanine in the former cocrystal and to the side chain carboxylate group of Asp or Glu in the latter proteins, (b) O(6) of guanine accepts hydrogen bond(s) from main-chain NH group(s), and (c) the purine moiety is sandwiched between aromatic (or hydrophobic) amino acid side chains.
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PMID:The specific guanine binding site of the ribonuclease T1 family enzymes and of G-proteins is modeled in the cocrystal formed by 7-methylguanosine-5'-phosphate and phenylalanine. 250 38

The antiproliferative action of the guanine-specific ribonuclease secreted by Bacillus intermedius (binase) was studied in different chicken and mouse cell lines. The proliferation rate of chicken embryo fibroblasts, either normal or Rous sarcoma virus-transformed, was significantly reduced by binase treatment. Among mouse fibroblasts, v-ras-transformed NIH3T3 cells were sensitive to binase, whereas the growth of non-transformed, v-src-transformed or v-fms-transformed NIH3T3 cells was not affected. A 48 h treatment with binase inhibited the Ca2+-dependent K+ current of v-ras-transformed NIH3T3 cells but had no effect on this membrane current in non-transformed and in v-src- or v-fms-transformed NIH3T3 cells. Our results suggest that mammalian cells expressing the ras-oncogene are a potential target for the antiproliferative action of binase.
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PMID:Bacillus intermedius ribonuclease as inhibitor of cell proliferation and membrane current. 1116 12

Ribonuclease Sa (pI = 3.5) from Streptomyces aureofaciens and its 3K (D1K, D17K, E41K) (pI = 6.4) and 5K (3K + D25K, E74K) (pI = 10.2) mutants were tested for cytotoxicity. The 5K mutant was cytotoxic to normal and v-ras-transformed NIH3T3 mouse fibroblasts, but RNase Sa and 3K were not. The structure, stability, and activity of the three proteins are comparable, but the net charge at pH 7 increases from -7 for RNase Sa to -1 for 3K and to +3 for 5K. These results suggest that a net positive charge is a key determinant of ribonuclease cytotoxicity. The cytotoxic 5K mutant preferentially attacks v-ras-NIH3T3 fibroblasts, suggesting that mammalian cells expressing the ras-oncogene are potential targets for ribonuclease-based drugs.
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PMID:Changing the net charge from negative to positive makes ribonuclease Sa cytotoxic. 1223 73