title: Preparation and characterisation of ribonuclease from human hypertrophic prostate gland (RNAase P2).
abstract: An endo-type, cyclising, 3'-phosphate-forming rebonuclease was purified to homogeneity from a water/Tween 80 extract of human hypertrophic prostate gland. The enzyme is acid- and heat- resistant and is optimally active at pH 7.0, 0.1 M NaCl. Molecular weight determined by gel filtration on Sephadex G-75 and sucrose density gradient centrifugation gave a mean value of 15 000. The prostatic ribonuclease is inhibited by Cu2+, bromoacetate and photooxidation in the presence of methylene blue. Other divalent ions, EDTA and p-chloromercuribenzoate have no influence on the enzymic activity. Prostatic RNase resembles RNase A in that it preferentially cleaves linkages in RNA after pyrimidine nucleotides to produce oligonucleotides terminated in cyclic 2',3' phosphate. The enzyme is inactive with poly(A) - poly(U) as substrate. Poly(U) is hydrolyzed four times as fast as poly(C), and 1.2 times as fast as RNA.
mesh_terms: D002413:Cations, Divalent; D002850:Chromatography, Gel; D004720:Endonucleases / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D008970:Molecular Weight; D011136:Polysorbates; D011467:Prostate / Q000201:enzymology*; D011470:Prostatic Hyperplasia / Q000201:enzymology*; D012260:Ribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature
chemical_list: D002413:Cations, Divalent; D011136:Polysorbates; D004720:Endonucleases; D012260:Ribonucleases