Histochemical studies of enzyme activities and structural elements in Gyrodactylus derjavini Mikailov, 1975 parasitizing fins of Oncorhynchus mykiss Walbaum were conducted. Marked activities of non-specific esterase, acid phosphatase, alkaline phosphatase and amino-peptidase were found in the intestinal caeca of the parasite. A strong activity of acetylcholinesterase was seen in the nervous system. Extraintestinal non-specific and eserine-sulphate resistant esterase was localized in the distal part of the hamulus sheath. Activities of peroxidase and glucuronidase were not detected. In the embryo, developing hamuli were enclosed in a sheath rich in phospholipids. Deposits of neutral lipids were sparse. The fully developed ventral and dorsal hamulus bars stained strongly for calcium. Lectin binding assays showed a mannose rich region in the cephalic duct openings, strong reactions for galactose in the glycocalyx whereas reactions for lactose were weak. These findings arc discussed with respect to the parasite-host relationship.
Študovali sme interakcie α-helikálneho peptidu acetyl-K2-L24-K2-amid (L24) s lipidovými dvojvrstvami z dimyristoylfosfatidylcholínu (DMCP) v gélovom (T = 288 K) a tekutokryštalickom (T = 310 K) stave za použitia metód molekulovej dynamiky. Ukázali sme, že napriek veĺkým fluktuáciam v koncových oblastiach polárnych částí membrány, v hydrofóbnom jadre membrány zostalo α-helikálne usporiadanie peptidu zachované. Peptid spôsobil zvýšenie neusporiadanosti v gélovom stave, kým v tekutokryštalickom stave došlo k zvýšeniu usporiadania membrány v porovnaní so stavom lipidov vzdialených od peptidu. Tieto rozdiely sú typické pre prvú polovicu membrány, kým v centrálnych častiach nedošlo k zmenám v usporiadaní. Na konci 10 ns simulácie bol peptid naklonený ku kolmici na povrch membrány pod uhlom 13° v gélovom a 33° v tekutokryštalickom stave. Simulácie vykonané v časoch 5 ns, respektíve 10 ns sa výrazne nelíšili., Milan Melicherčík, Ján Urban, Tibor Hianik., and Obsahuje seznam literatury