Document Detail

Purification and properties of acid ribonucleases in human serum and leukocytes.
MedLine Citation:
PMID:  26464     Owner:  NLM     Status:  MEDLINE    
Acid RNase was purified from normal human serum about 2400-fold by chromatography on phosphocellulose and Sephadex G-75 and rechromatography on Sephadex G-75. Assayed with yeast RNA as substrate, the enzyme showed the maximal activity at about pH 6.5 with sodium phosphate buffer. The reaction was activated by Na+, K+, and spermine, but it was not affected greatly by Mg2+, Co2+, and EDTA. Ca2+, Fe2+, Zn2+, and Cu2+ inhibited the reaction. Among the synthetic substrates examined, the enzyme preferentially hydrolyzed pyrimidine nucleotides, with a higher affinity for polycytidylate than for polyuridylate. The enzyme was thermolabile, but it stabilized with bovine plasma albumin. The molecular weight was approximately 15,000, estimated gel filtration on Sephadex G-75, and its isoelectric pH was above 11.0. From normal human leukocytes, acid RNase was purified about 400-fold by the same procedure described previously except that rechromatography on Sephadex G-75 was omitted. The properties of leukocytic RNase were found to be similar to those of serum acid RNase, but the latter enzyme differed in substrate specificity substantially from leukocytic RNase, preferring polyuridylate to polycytidylate. This evidence shows that serum RNase is not of leukocytic origin under normal physiological conditions.
K Akagi; M Yamanaka; K Murai; T Omae
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Cancer research     Volume:  38     ISSN:  0008-5472     ISO Abbreviation:  Cancer Res.     Publication Date:  1978 Jul 
Date Detail:
Created Date:  1978-08-14     Completed Date:  1978-08-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2984705R     Medline TA:  Cancer Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2163-7     Citation Subset:  IM    
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MeSH Terms
Chromatography, Gel
Enzyme Activation
Hydrogen-Ion Concentration
Leukocytes / enzymology*
Molecular Weight
Poly C / metabolism
Poly U / metabolism
Ribonucleases / antagonists & inhibitors,  blood*,  isolation & purification
Substrate Specificity
Reg. No./Substance:
27416-86-0/Poly U; 30811-80-4/Poly C; EC 3.1.-/Ribonucleases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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