Sandbox Reserved 192: Difference between revisions
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Another member in the ribonuclease family and structural homologue to bovine RNase A is frog onconase [http://en.wikipedia.org/wiki/Onconase] or ONC. ONC is found in oocytes [http://en.wikipedia.org/wiki/Oocytes] and early embryos of northern leopard frogs. The frog ribonuclease variant shows both cytostatic (cell growth suppression) and cytotoxic (prevents cell divisions) characteristics when it interacts with tumor cells. According to Gahl et al. (2008), no side effects have been determined for ONC. Leland et al. (2001) looked to determine the interactions that control the folding of ONC in order to develop effective mimics of ONC. In order to determine the interactions that controlled folding, the regeneration of RNase A was studied. Although RNase A and ONC were structurally very similar, there were significant differences in their folding pathways. While ONC forms a stable disulfide intermediate, RNase A does not. ONC was also found to be missing a disulfide bond that RNase A possesses. In the case of both enzymes, entropy is lost in the formation of the disulfide bonds, but folding may be driven by enthalpically favorable interactions of the side chains. Further experiments are being done to identify intramolecular interactions that account for the increased rate and formation of the structured intermediate in ONC (Gahl). | Another member in the ribonuclease family and structural homologue to bovine RNase A is frog onconase [http://en.wikipedia.org/wiki/Onconase] or ONC. ONC is found in oocytes [http://en.wikipedia.org/wiki/Oocytes] and early embryos of northern leopard frogs. The frog ribonuclease variant shows both cytostatic (cell growth suppression) and cytotoxic (prevents cell divisions) characteristics when it interacts with tumor cells. According to Gahl et al. (2008), no side effects have been determined for ONC. Leland et al. (2001) looked to determine the interactions that control the folding of ONC in order to develop effective mimics of ONC. In order to determine the interactions that controlled folding, the regeneration of RNase A was studied. Although RNase A and ONC were structurally very similar, there were significant differences in their folding pathways. While ONC forms a stable disulfide intermediate, RNase A does not. ONC was also found to be missing a disulfide bond that RNase A possesses. In the case of both enzymes, entropy is lost in the formation of the disulfide bonds, but folding may be driven by enthalpically favorable interactions of the side chains. Further experiments are being done to identify intramolecular interactions that account for the increased rate and formation of the structured intermediate in ONC (Gahl). | ||
<Structure load='7RSA' size='300' frame='true' align='left' caption=' | <Structure load='7RSA' size='300' frame='true' align='left' caption='RNase A' scene='Sandbox_Reserved_192/Second_rnase_structure_blue/1' /> | ||
=='''Further Research with the Hydrophobic Core'''== | =='''Further Research with the Hydrophobic Core'''== | ||