| dc.creator | RIVAS,MARIELLA | |
| dc.creator | GARCÍA,CARLOS | |
| dc.creator | LIBERONA,JOSÉ L | |
| dc.creator | LAGOS,NÉSTOR | |
| dc.date | 2000-01-01 | |
| dc.date.accessioned | 2019-05-02T21:20:59Z | |
| dc.date.available | 2019-05-02T21:20:59Z | |
| dc.identifier | https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000300005 | |
| dc.identifier.uri | http://revistaschilenas.uchile.cl/handle/2250/81339 | |
| dc.description | Protein phosphatases are involved in many cellular processes. One of the most abundant and best studied members of this class is protein phosphatase type-2A (PP2A). In this study, PP2A was purified from the mussel Mytilus chilensis. Using both SDS-PAGE and size exclusion gel filtration under denaturant conditions, it was confirmed that the PP2A fraction was essentially pure. The isolated enzyme is a heterodimer and the molecular estimated masses of the subunits are 62 and 28 kDa. The isolated PP2A fraction has a notably high p-NPP phosphatase activity, which is inhibited by NaCl. The hydrolytic p-NPP phosphatase activity is independent of the MgCl2 concentration. The time courses of the inhibition of the PP2A activity of p-NPP hydrolysis by increasing concentrations of three phycotoxins that are specific inhibitors of PP2A are shown. Inhibitions caused by Okadaic acid, dinophysistoxin-1 (DTX1, 35-methylokadiac acid) and Microcystine L-R are dose-dependent with inhibition constants (Ki) of 1.68, 0.40 and 0.27 nM respectively. Microcystine L-R, the most potent phycotoxin inhibitor of PP2A isolated from Mytilus chilensis with an IC50 = 0.25 ng/ml, showed the highest specific inhibition effect an the p-NPP hydrolisis. The calculated IC50 for DTX1 and OA was 0.75 ng/ml and 1.8 ng/ml respectively. | |
| dc.format | text/html | |
| dc.language | en | |
| dc.publisher | Sociedad de Biología de Chile | |
| dc.relation | 10.4067/S0716-97602000000300005 | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.source | Biological Research v.33 n.3-4 2000 | |
| dc.subject | Chile | |
| dc.subject | Diarrhetic Shellfish Poisoning (DSP) | |
| dc.subject | Mussel | |
| dc.subject | Mytilus chilensis | |
| dc.subject | Protein Phosphatase 2A | |
| dc.subject | Microcystine L-R | |
| dc.title | Biochemical characterization and inhibitory effects of dinophysistoxin-1, okadaic acid and microcystine l-r on protein phosphatase 2a purified from the mussel Mytilus chilensis. | |
