RÉSUMÉ
Arthropod hemocyanins (Hcs) are a family of large extracellular oxygen-transporting proteins with high molecular mass and hexameric or multi-hexameric molecular assembly. This study reports for the first time the isolation and characterization of the structure of an arthropod hemocyanin from crab Eriphia verrucosa (EvH) living in the Black Sea. Its oligomeric quaternary structure is based on different arrangements of a basic 6 × 75 kDa hexameric unit, and four of them (EvH1, EvH2, EvH3, and EvH4) were identified using ion-exchange chromatography. Subunit 3 (EvH3) shows high similarity scores (75.0, 87.5, 91.7, and 75.0 %, respectively) by comparison of the N-terminal sequence of subunit 1 from Cancer pagurus of the North Sea (Cp1), subunits 3 and 6 of Cancer magister (Cm3 and Cm6), and subunit 2 of Carcinus aestuarii (CaSS2), respectively. Moreover, a partial cDNA sequence (1309 bp) of E. verrucosa hemocyanin encoding a protein of 435 amino acids was isolated. The deduced amino acid sequence shows a high degree of similarity with subunits 3, 4, 5, and 6 of C. magister (81-84 %). Most of the hemocyanins are glycosylated, and three putative O-linkage sites were identified in the partial amino acid sequence of EvH at positions 444-446, 478-480, and 547-549, respectively. The higher stability of native Hc in comparison to its subunit EvH4 as determined by circular dichroism (CD) could be explained with the formation of a stabilizing quaternary structure.
Sujet(s)
Brachyura/métabolisme , Hémocyanine/composition chimique , Séquence d'acides aminés , Animaux , Séquence nucléotidique , Sites de fixation/génétique , Brachyura/génétique , Chromatographie en phase liquide à haute performance , Chromatographie d'échange d'ions , Clonage moléculaire , Femelle , Hémocyanine/génétique , Hémocyanine/isolement et purification , Données de séquences moléculaires , Réaction de polymérisation en chaîne , Structure quaternaire des protéines , Spectrométrie de masse MALDIRÉSUMÉ
During the development of a Czechoslovak silicone cannula for reconstructive surgery of the lacrimal passage-ways was elaborated the modification for the congenital obstruction. The surgical method imoles the probing and cannulation at the same time. probe with fixed cannula passed delicately through nasolacrimal duct via the upper or lower canaliculus to saccus lacrimalis. This probe overcomes the lateral part of the nose on the inspection of otorhinolaryngologist. The end of cannula was fixed by the stitch to skin near lacrimal punctum. The silicone tubing is left in situ for about three months.