Avtor/Urednik		Lenasi, Helena
Naslov		Steroid binding by a spontaneously formed dichlorophenolindophenol-polymer
Prevedeni naslov		Vezava steroidov na spontano nastali polimer diklorofenolindofenola
Tip		članek
Vir		Farm Vestn
Vol. in št.		Letnik 49, št. 3
Leto izdaje		1998
Obseg		str. 273-9
Jezik		eng
Abstrakt		In studies on steroid binding molecules of filamentous fungi 2,6-dichlorophenol-indophenol (DPIP) was used to provide an appropriate redox state of the cytosol. After standing at room temperature for some days DPIP transformed in such a way that it became able to bind specifically progesterone and androgens. Binding and some other characteristics of modified DPIP were examined: the compound had a high affimity for progesterone ( Kd - 6.5 nM); (3H)progesterone was effectively displaced by testosterone and 21(OH)progesterone, weaker competitors were nortestosterone, 11 alpha progesterone, dexamethasone and estrone, whereas cholestenone did not compete with progesterone for modified DPIP. This compoud seemed to be a polymer of not defined lenght; molecules of Mr>50000 exhibited specific binding ability for stereoids. In addition to covalent interactions present in the polymer, it is likely that hydrophobic and ionic interactions are also involved inthe three-dimensional structure. The binding characteristics of DPIP-polymer resemble the binding characteristics of natural receptors. This fact is very interesting since both type of molecules are composed of chemically completely different units yet they are both able to form the threedimensional binding site for selected steroids.
Izvleček		Pri proučevanju vezavnih molekulr za steoide v filamentoznih glivah smo uporabili 2,6-diklorofenolindefonol (DPIP) z namenom, da bi zagotovili odgovarjajoči redoks potencial v citosolu. Ob tem se je pokazalo, da se je DPIP med stanjem v vodni raztopini pri sobni temperaturi kemijsko spremenil in pričel specifično vezati steroide. Določili smo nekaj vezavnih in drugih lastnosti tako spremenjenega DPIP: spojina je imela veliko afiniteto do progesterona (Kd - 6,5 nM); testosteron in21(OH)progesteron sta povsem izpodrinila (3H)progresteron z vezavnega mesta, medtem ko so bili nortestosteron, 11 alpha progesteron, deksametazon in estron uinkoviti, holestenon pa sploh ni kompetiral s (3H)progresteronom. Verjetno je bila spojina polimer nedefinirane dolžine; molekule z M, > 50000 so specifično vezale steoide. Za vzdrževanje trodimenzionalne strukture polimera so bile razen kovalentnih vezi po vsej verjetnosti vključene tudi hidrofobne in ionske interakcije. Vezavne lastnosti polimera DPIP so podobne vezavnim lastnostim naravnih receptorjev in so kot takšne zelo zanimive, saj sta ti dve vrsti makromolekul sestavljene iz kemijsko povsem različnih enot, ki pa ustvarjajo podobno trodimenzionalno vezavno mesto za izbrane steoide.
Deskriptorji		RHIZOPUS CYTOSOL CHLOROBENZENES OXIDATION-REDUCTION STEROIDS FUNGI BINDING SITES PROGESTERONE NANDROLONE DEXAMETHASONE ESTRONE ASCOMYCETES