[The mechanism of formation of emitter by fluorescence of calcium-discharged obelin].

It is known that bioluminescence of obelin is triggered by Ca2+ the binding of which to the protein induces the decarboxylation of 2-hydroperoxycoelenterazine. The molecular mechanism of fluorescence of obelin, which determines the fluorescence of see hydroid Obelia Longissima, has been investigated with the use of quantum chemical calculations. According to quantum chemical calculations, the emitter of the reaction is the ion-pair state of phenolate-anion of coelenteramide.

[Calcium-regulated photoproteins of marine coelenterates].

Ca(2+)-regulated photoproteins are bioluminescent proteins responsible for bioluminescence of marine coelenterates. The photoprotein molecule is a stable enzyme-substrate complex consisting of a single polypeptide chain and an oxygen "pre-activated" substrate, 2-hydroperoxycoelenterazine, which is tightly but non-covalently bound with a protein. The bioluminescence is triggered by calcium ions and originates from an oxidative decarboxylation of a protein bound substrate.

[Conjugates of the Ca2+ -regulated photoprotein obelin with immunoglobulins: synthesis and use as labels in bioluminescent immunoassay].

An efficient procedure for obelin conjugation with immunoglobulins was developed. The possibility was shown of using the resulting conjugates instead of a radioisotope label for the immunoassay of thyroid stimulating hormone in sera; the conjugates provide a sensitivity of 0.01 microIU/ml.

[The Ca2+-activated photoprotein obelin as a calcium transport inducer in proteoliposomes in the membrane of the T-system of skeletal muscles].

The calcium-binding photoprotein obelin extracted and purified from the luminescent hydroid Obelia longissima was used to record the processes of Ca2+ release from proteoliposomes. It has been shown that lecithin proteoliposomes with incorporated rabbit skeletal muscle T-system membranes possess a BAY K-8644-activated permeability which is inhibited by nitrendipine. The Ca(2+)-activated photoprotein obelin is a convenient and perspective tool in studies of fast calcium fluxes.