RESUMO
OBJECTIVE@#To investigate the multienzyme complex formation of human malaria parasite Plasmodium falciparum (P. falciparum) orotate phosphoribosyltransferase (OPRT) and orotidine 5'-monophosphate decarboxylase (OMPDC), the fifth and sixth enzyme of the de novo pyrimidine biosynthetic pathway. Previously, we have clearly established that the two enzymes in the malaria parasite exist physically as a heterotetrameric (OPRT)2(OMPDC)2 complex containing two subunits each of OPRT and OMPDC, and that the complex have catalytic kinetic advantages over the monofunctional enzyme.@*METHODS@#Both enzymes were cloned and expressed as recombinant proteins. The protein-protein interaction in the enzyme complex was identified using bifunctional chemical cross-linker, liquid chromatography-mass spectrometric analysis and homology modeling.@*RESULTS@#The unique insertions of low complexity region at the α 2 and α 5 helices of the parasite OMPDC, characterized by single amino acid repeat sequence which was not found in homologous proteins from other organisms, was located on the OPRT-OMPDC interface. The structural models for the protein-protein interaction of the heterotetrameric (OPRT)2(OMPDC)2 multienzyme complex were proposed.@*CONCLUSIONS@#Based on the proteomic data and structural modeling, it is surmised that the human malaria parasite low complexity region is responsible for the OPRT-OMPDC interaction. The structural complex of the parasite enzymes, thus, represents an efficient functional kinetic advantage, which in line with co-localization principles of evolutional origin, and allosteric control in protein-protein-interactions.
Assuntos
Humanos , Sequência de Aminoácidos , Malária Falciparum , Parasitologia , Modelos Moleculares , Dados de Sequência Molecular , Orotato Fosforribosiltransferase , Química , Genética , Metabolismo , Orotidina-5'-Fosfato Descarboxilase , Química , Genética , Metabolismo , Plasmodium falciparum , Genética , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas de Protozoários , Química , Genética , Metabolismo , Proteínas Recombinantes , Química , Genética , Metabolismo , Alinhamento de SequênciaRESUMO
OBJECTIVE To attend to the importance and issues of using the enzyme cleaner for the reprocessing of medical instrument. METHODS The principle, usage, precautions, and the selection of enzyme cleaner were analyzed. RESULTS The cleaning of the medical instrument must use the liquid enzyme detergent that has the following characters: clear solution, no or low foam, free rinsing, flexibilities to the water temperature, and no limitation to the water quality. CONCLUSIONS For successful cleaning of the medical instrument the use of the high-quality enzyme cleaner is required. A complete cleaning of the medical instrument is the first step to assure the quality of disinfection, sterilization, and the infection control.