RESUMO
Perlucin is one of the proteins of the organic matrix of nacre (mother of pearl) playing an important role in biomineralisation. This nacreous layer can be predominately found in the mollusc lineages and is most intensively studied as a compound of the shell of the marine Australian abalone Haliotis laevigata. A more detailed analysis of Perlucin will elucidate some of the still unknown processes in the complex interplay of the organic/inorganic compounds involved in the formation of nacre as a very interesting composite material not only from a life science-based point of view. Within this study we discovered three unknown Perlucin splice variants of the Australian abalone H. laevigata. The amplified cDNAs vary from 562 to 815 base pairs and the resulting translation products differ predominantly in the absence or presence of a varying number of a 10 mer peptide C-terminal repeat. The splice variants could further be confirmed by matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-ToF MS) analysis as endogenous Perlucin, purified from decalcified abalone shell. Interestingly, we observed that the different variants expressed as maltose-binding protein (MBP) fusion proteins in E. coli showed strong differences in their influence on precipitating CaCO3 and that these differences might be due to a splice variant-specific formation of large protein aggregates influenced by the number of the 10 mer peptide repeats. Our results are evidence for a more complex situation with respect to Perlucin functional regulation by demonstrating that Perlucin splice variants modulate the crystallisation of calcium carbonate. The identification of differentially behaving Perlucin variants may open a completely new perspective for the field of nacre biomineralisation.
Assuntos
Carbonato de Cálcio/química , Gastrópodes/genética , Lectinas/genética , Nácar/metabolismo , Isoformas de Proteínas/genética , Animais , Teorema de Bayes , Western Blotting , Células COS , Chlorocebus aethiops , Biologia Computacional , Cristalização , Primers do DNA/genética , DNA Complementar/genética , Eletroforese em Gel Bidimensional , Escherichia coli , Gastrópodes/metabolismo , Lectinas/metabolismo , Proteínas Ligantes de Maltose/metabolismo , Modelos Genéticos , Filogenia , Plasmídeos/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Marburg University Medical Center has been introducing a comprehensive health information system since 1999, using a single-vendor application framework with an integrated generator tool for the development of clinical applications. To find out if this architecture and our participative software engineering approach can be considered a step towards a responsive infrastructure, we compared the situation after the first deployment phase (basically a holistic approach) with the situation after the system was further developed and adapted to the users' needs using the generator tool approach. We collected system statistics and conducted user satisfaction surveys in 2001/02 and 2003 using standardized measurements. The survey results showed that user involvement as well as system content were judged significantly higher after the second deployment phase. Insofar, we could demonstrate the feasibility of our approach. However, definite statements concerning the superiority of the generator tool approach to other concepts are not yet possible. We will continue our assessment, and we strongly suggest further studies in other institutions introducing comparable clinical functionality.