RESUMO
Conjugates of pancreatic RNase and ligand-free human serum albumin (LFHSA) have been obtained. The number of hydrophobic binding sites both for initial HSA and LFHSA has been determined by the polarised luminescence method. Interaction between RNase and HSA involves additional electrovalent linkage. Unlike initial enzyme, conjugates exhibit activity toward double-strand RNA. After intravenous injection, transferase activity of unmodified enzyme remains in the blood during 20 min., whereas 30-40% of this activity is detected at the fourth day after administration of RNase conjugates. A single dose administration of LFHSA-RNAse conjugates exhibited high antiviral activity in mice, infected with influenza A and influenza B viruses.
Assuntos
Ribonuclease Pancreático/química , Albumina Sérica/química , Animais , Sítios de Ligação , Humanos , Ligantes , Taxa de Depuração Metabólica , Coelhos , Ratos , Ratos Wistar , Ribonuclease Pancreático/metabolismo , Ribonuclease Pancreático/farmacocinética , Albumina Sérica/metabolismo , Albumina Sérica/farmacocinética , Distribuição TecidualRESUMO
The efficiency of the binding of RNase 7P molecules to albumin on cocondensation with the aim of producing the prolonged action forms of the enzyme can be increased by using ligand-free human serum albumin (LFHSA). The CD method showed that LFHSA underwent changes of the cooperative character under the action of acid and urea. On potentiometric titration the number of titrated groups of LFHSA decreased with time. The GPC method demonstrated the RNase bound more efficiently to freshly dissolved LFHSA. In this case part of the enzymic activity was manifested only after proteolysis of the albumin carrier. Cocondensation with the aid of glutaraldehyde resulted in the formation of LFHSA-RNase conjugates composed of 1-2 moles of human serum albumin and 1-6 moles of RNase. More than 50% of transferase activity retained in the blood plasma for 2-3 days after intravenous injection of the conjugates with a molecular weight of 70-80 kD to rabbits.
Assuntos
Bacillus/enzimologia , Ribonucleases/metabolismo , Albumina Sérica/metabolismo , Animais , Dicroísmo Circular , Glutaral , Humanos , Hidrólise , Ligantes , Potenciometria , Coelhos , Ribonucleases/química , Albumina Sérica/químicaAssuntos
Infecções por Chlamydia , Chlamydia trachomatis , Chlamydophila pneumoniae , Psitacose , Animais , Infecções por Chlamydia/diagnóstico , Infecções por Chlamydia/microbiologia , Chlamydia trachomatis/patogenicidade , Chlamydia trachomatis/fisiologia , Chlamydophila pneumoniae/patogenicidade , Chlamydophila pneumoniae/fisiologia , Feminino , Humanos , Testes Imunológicos , Masculino , Psitacose/diagnóstico , Psitacose/microbiologia , Zoonoses/microbiologiaRESUMO
In order to obtain nuclease and human serum albumin (HSA) conjugates with a high enzyme content it is proposed to use a ligand-free HSA. The ligands are removed with the help of a strong anion exchanger. A two-stage procedure of conjugate preparation is proposed. It consists in the complexation of ligand-free HSA and enzyme and subsequent co-condensation of protein molecules of the poly-complex with the aid of glutaric aldehyde. When the conjugates are administered to rabbits intravenously, the RNAase activity is manifested in blood for 3-5 days. Moreover, in the case of conjugates with a molecular weight of 80 kDa, the prolongation time is greater than for conjugate with a higher molecular weight.
Assuntos
Ribonucleases/química , Albumina Sérica/química , Animais , Bacillus/enzimologia , Reagentes de Ligações Cruzadas , Enzimas Imobilizadas , Glutaral , Humanos , Ligantes , Peso Molecular , Pâncreas/enzimologia , Coelhos , Ribonucleases/administração & dosagem , Ribonucleases/sangue , Albumina Sérica/administração & dosagem , Albumina Sérica/metabolismo , Fatores de TempoRESUMO
Conjugates containing blood serum albumin and pancreatic ribonuclease, produced by means of polycondensation reaction, exhibited higher half-life in rabbit circulation as compared with non-modified enzyme. Presence of the protein-carrier contributed to elevation of the ribonuclease therapeutic efficiency and enabled to decrease the quantity of injections.
Assuntos
Ribonuclease Pancreático/química , Albumina Sérica/química , Animais , Preparações de Ação Retardada , Portadores de Fármacos , Meia-Vida , Coelhos , Ribonuclease Pancreático/administração & dosagem , Ribonuclease Pancreático/síntese química , Ribonuclease Pancreático/farmacocinética , Albumina Sérica/síntese químicaRESUMO
The effect of remantadine on the course of influenzal-staphylococcal infection was studied in white mice. When the drug was injected to the mice infected with remantadine-sensitive strain of influenza A virus and Staphylococcus the lethality decreased from 93.3% to 26.7%, the survival time increased from 3.8 to 10.1 days, the incidence of pneumonia decreased from 85.7% to 48.7%, the average intensity of pneumonia decreased from 66.4% to 9.9%, and virus titres in the lungs decreased by 3.5-4.0 lg EID50 (p less than 0.05). In the groups of mice infected with remantadine-resistant strain of influenza virus and Staphylococcus remantadine showed no significant effect on these parameters: the lethality decreased by 6.7% only, the average survival time increased only by 0.33 days, the incidence of pneumonia decreased by 9%, its intensity by 19.2%; influenza virus titres in the lung tissue did not change significantly.