Naslov
Inhibition of alkaline phosphatase activity by okadaic acid, a protein phosphatase inhibitor

Autori
Meštrović, Vedrana ; Pavela-Vrančič, Maja

Izvornik
Biochimie (0300-9084) 85 (2003), 7; 647-650

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
phycotoxins; okadaic acid; alkaline phosphatase; non-competitive inhibition

Sažetak
This paper reports on a potential physiological target of okadaic acid (OA), the toxin metabolite responsible for shellfish poisoning and, consequently, human intoxication. OA is a potent promotor of tumor activity, most likely by inhibiting protein phosphatase 1 and 2A [Fujiki H., Suganuma M., Adv. Cancer. Res. 61 (1993) 143-194]. However, all of its cellular targets have not yet been characterized. The interaction of OA with alkaline phosphatase (ALP) has been investigated in view of its protein phosphatase inhibition activity. Kinetic analysis of ALP from E. coli, human placental and calf intestinal ALP has shown that OA acts as a non-competitive inhibitor of ALP. The bacterial enzyme displays a higher affinity for OA (Ki 360 nM) than the eukaryotic proteins (human placental ALP, Ki 2.05 μ M ; calf intestinal ALP, Ki 3.15 μ M). The inhibition by OA suggests a putative role of ALP in the phosphorylation status, through regulation of the phosphorylation/dephosphorylation equilibrium of proteins with phosphoseryl or phosphothreonyl residues.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija

POVEZANOST RADA