RESUMO
Heparinoids and related negatively-charged substances caused suppression of the penicillin-induced bacteriolysis of staphylococci and a higher viability rate. Furthermore, the penicillin-induced release of cell wall material was reduced by these substances. The main reason for this suppression of bacteriolysis was an inhibition of the activity of cell wall autolytic enzymes while the penicillin-specific perturbations of wall morphogenesis were not affected.
Assuntos
Anticoagulantes/farmacologia , Bacteriólise/efeitos dos fármacos , Penicilina G/antagonistas & inibidores , Staphylococcus aureus/efeitos dos fármacos , Microscopia Eletrônica , Staphylococcus aureus/ultraestruturaRESUMO
Liquoid (polyanethole sulfonate) was neither capable of influencing the growth nor the viability of staphylococci. But liquoid induced a suppression of the activity of different autolytic wall systems of normally growing staphylococci, i.e., autolysins which participate in cross wall separation as well as autolysins which are responsible for cell wall turnover. Additionally, the lysostaphin-induced wall disintegration of staphylococci was inhibited by liquoid. However, no indication could be found for a direct inhibition of lytic wall enzymes by liquoid; rather an interaction of liquoid with the target structure for the autolytic wall enzymes, the cell wall itself, was postulated. On the basis of the experimental data with the teichoic acid- mutant S. aureus 52A5 the sites of wall teichoic acid were supposed to be an important target for the binding of liquoid to the staphylococcal cell wall.
Assuntos
Benzenossulfonatos/farmacologia , Polianetolsulfonato/farmacologia , Staphylococcus aureus/metabolismo , Bacteriólise , Parede Celular/efeitos dos fármacos , Parede Celular/enzimologia , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Lisostafina/farmacologia , Microscopia Eletrônica de Varredura , Mutação , Staphylococcus aureus/genética , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/ultraestruturaRESUMO
The complete amino acid sequence of the light chain of human blood coagulation factor X has been determined by automated Edman degradation of peptides isolated from chemical and enzymatic digests of the carboxymethylated light chain. The protein consists of 139 amino acid residues, which include 11 residues of gamma-carboxyglutamic acid. The first 100 residues of the human factor X light chain exhibit approximately 80% homology when compared to the amino-terminal sequence of bovine factor X light chain. This homology decreases to approximately 50% in the remaining 39 residues of the carboxyl-terminal region of the protein. Proton nuclear magnetic resonance spectroscopy and mass spectrometry analyses of isolated residue 63 identified this residue as L-erythro-beta-hydroxyaspartic acid, a hitherto unrecognized amino acid in proteins. Evidence is also presented for the presence of this residue in the corresponding regions of the light chains of bovine factor X and bovine protein C. The biological function of beta-hydroxyaspartic acid in these proteins is unknown.
