Biology:Pancreatic ribonuclease

From HandWiki
Pancreatic ribonuclease
RNase A.png
Structure of RNase A
Identifiers
EC number3.1.27.5
CAS number9001-99-4
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
Pancreatic ribonuclease
Identifiers
SymbolRNaseA
PfamPF00074
InterProIPR001427
SMARTSM00092
PROSITEPDOC00118

Pancreatic ribonucleases (EC 3.1.27.5, RNase, RNase I, RNase A, pancreatic RNase, ribonuclease I, endoribonuclease I, ribonucleic phosphatase, alkaline ribonuclease, ribonuclease, gene S glycoproteins, Ceratitis capitata alkaline ribonuclease, SLSG glycoproteins, gene S locus-specific glycoproteins, S-genotype-assocd. glycoproteins, ribonucleate 3'-pyrimidino-oligonucleotidohydrolase) are pyrimidine-specific endonucleases found in high quantity in the pancreas of certain mammals and of some reptiles.[1]

Specifically, the enzymes are involved in endonucleolytic cleavage of 3'-phosphomononucleotides and 3'-phosphooligonucleotides ending in C-P or U-P with 2',3'-cyclic phosphate intermediates. Ribonuclease can unwind the RNA helix by complexing with single-stranded RNA; the complex arises by an extended multi-site cation-anion interaction between lysine and arginine residues of the enzyme and phosphate groups of the nucleotides.

Notable family members

Bovine pancreatic ribonuclease is the best-studied member of the family and has served as a model system in work related to protein folding, disulfide bond formation, protein crystallography and spectroscopy, and protein dynamics.[2] Human genome contains 8 genes that share the structure and function with bovine pancreatic ribonuclease, with 5 additional pseudo-genes. These structure and dynamics of these enzymes are related to their diverse biological functions.[3]

Other proteins belonging to the pancreatic ribonuclease superfamily include: bovine seminal vesicle and brain ribonucleases; kidney non-secretory ribonucleases;[4] liver-type ribonucleases;[5] angiogenin, which induces vascularisation of normal and malignant tissues; eosinophil cationic protein,[6] a cytotoxin and helminthotoxin with ribonuclease activity; and frog liver ribonuclease and frog sialic acid-binding lectin. The sequence of pancreatic ribonucleases contains four conserved disulfide bonds and three amino acid residues involved in the catalytic activity.[7]

Human genes

Human genes encoding proteins containing this domain include:

  • ANG,
  • RNASE1, RNASE10, RNASE12, RNASE2, RNASE3, RNASE4, RNASE6, RNASE7, and RNASE8.

Cytotoxicity

Some members of the pancreatic ribonuclease family have cytotoxic effects. Mammalian cells are protected from these effects due to their extremely high affinity for ribonuclease inhibitor (RI), which protects cellular RNA from degradation by pancreatic ribonucleases.[8] Pancreatic ribonucleases that are not inhibited by RI are approximately as toxic as alpha-sarcin, diphtheria toxin, or ricin.[9]

Two pancreatic ribonucleases isolated from the oocytes of the Northern leopard frog - amphinase and ranpirnase - are not inhibited by RI and show differential cytotoxicity against tumor cells.[10] Ranpirnase was studied in a Phase III clinical trial as a treatment candidate for mesothelioma, but the trial did not demonstrate statistical significance against primary endpoints.[11]

References

  1. "Comparison of the structure of turtle pancreatic ribonuclease with those of mammalian ribonucleases". FEBS Lett. 194 (2): 338–343. 1986. doi:10.1016/0014-5793(86)80113-2. PMID 3940901. 
  2. "Back to the future: ribonuclease A". Biopolymers 90 (3): 259–77. 2008. doi:10.1002/bip.20845. PMID 17868092. 
  3. "Conservation of Dynamics Associated with Biological Function in an Enzyme Superfamily.". Structure 26 (3): 426–436. Mar 2018. doi:10.1016/j.str.2018.01.015. PMID 29478822. 
  4. "Molecular cloning of the human eosinophil-derived neurotoxin: a member of the ribonuclease gene family". Proc. Natl. Acad. Sci. U.S.A. 86 (12): 4460–4464. 1989. doi:10.1073/pnas.86.12.4460. PMID 2734298. 
  5. "Primary structure of a ribonuclease from porcine liver, a new member of the ribonuclease superfamily". Biochemistry 28 (25): 9806–9813. 1989. doi:10.1021/bi00451a040. PMID 2611266. 
  6. "Human eosinophil cationic protein. Molecular cloning of a cytotoxin and helminthotoxin with ribonuclease activity". J. Exp. Med. 170 (1): 163–176. 1989. doi:10.1084/jem.170.1.163. PMID 2473157. 
  7. "Ribonuclease A". Chem. Rev. 98 (3): 1045–1066. 1998. doi:10.1021/cr960427h. PMID 11848924. 
  8. Gaur, D; Swaminathan, S; Batra, JK (6 July 2001). "Interaction of human pancreatic ribonuclease with human ribonuclease inhibitor. Generation of inhibitor-resistant cytotoxic variants.". The Journal of Biological Chemistry 276 (27): 24978–84. doi:10.1074/jbc.m102440200. PMID 11342552. 
  9. Saxena, SK; Rybak, SM; Winkler, G; Meade, HM; McGray, P; Youle, RJ; Ackerman, EJ (5 November 1991). "Comparison of RNases and toxins upon injection into Xenopus oocytes.". The Journal of Biological Chemistry 266 (31): 21208–14. PMID 1939163. 
  10. "Ribonucleases as novel chemotherapeutics : the ranpirnase example". BioDrugs 22 (1): 53–58. 2008. doi:10.2165/00063030-200822010-00006. PMID 18215091. 
  11. "Alfacell Annual Report 2009". http://www.alfacell.com/annualreport2009.pdf. 
This article incorporates text from the public domain Pfam and InterPro: IPR001427