ABSTRACT
Zn(2+) and Co(2+) ions are known to promote human growth hormone reversible dimerization. In these studies, dimerization was also shown to be initiated by nine other metal ions: Cd(2+), Hg(2+), Cu(2+), Ag+, Au(3+), Au+, Pd(2+), Ni(2+), and Pt(4+). In some cases (Hg(2+), Ag(+), Au(3+), and Ni(2+)) formation of higher oligomers also took place. In addition further detailed investigation of dimerization in the presence of Zn(2+) ions was carried out.
Subject(s)
Human Growth Hormone/chemistry , Metals, Heavy/pharmacology , Amino Acid Sequence , Cations , Cross-Linking Reagents , Dimerization , Human Growth Hormone/drug effects , Humans , Molecular Sequence Data , Peptide Fragments/chemistry , Triazines/pharmacology , TrypsinABSTRACT
Chelation of mercuric ions by an iminodiacetate-Sepharose gel was evaluated. The retentive properties of iminodiacetate-Sepharose gel column was studied towards proteins varying the composition of eluting systems from 2-mercaptoethanol to NaCl and imidazole, determining also the extent of mercury leaching. It was demonstrated that chelated mercury contained free sites for interaction with proteins such as bromelain and recombinant human granulocyte colony stimulating factor from E. coli. The extraction of the latter by chromatography of its inclusion bodies solution on Hg(II)-loaded Sepharose-iminodiacetate gel was also evaluated.
Subject(s)
Bromelains/isolation & purification , Chromatography, Affinity/methods , Granulocyte Colony-Stimulating Factor/isolation & purification , Mercury/chemistry , Chelating Agents/chemistry , Electrophoresis, Polyacrylamide Gel , Humans , Recombinant ProteinsABSTRACT
The chelation capability of the reactive dye Light Resistant Yellow 2KT towards metal ions, particularly mercury(II) was evaluated in the pH range 5.0-7.0, and it was shown that the dye-Hg(II) complex has a free site for the interaction with human recombinant granulocyte-colony stimulating factor (rhG-CSF) from Escherichia coli. Affinity partitioning of three rhG-CSF forms--native, rhG-CSF[Cys17--->Ser17] and (His)6-rhG-CSF was studied in aqueous two-phase systems, which contained metal ions--Cu(II), Ni(II) and Hg(II)--chelated by dye-poly(ethylene glycol) at pH 5.0 and 7.0, in the presence or absence of many selected agents. It was determined, that chelated Ni(II) ions exhibited stronger interaction with the hexahistidine-tagged protein form, while the extraction power of Cu(II) ions was found to be of comparable order of magnitude for all three protein forms at pH 7.0. A comparative study of rhG-CSF and both its forms partitioning in the presence of chelated Hg(II) ions at pH 7.0 and 5.0 revealed possible direct interaction between Hg(II) ions and unpaired Cys-17 of rhG-CSF. The partitioning of three rhG-CSF forms inclusion body extract was studied in the presence of chelated Ni(II) and Hg(II) ions thus explaining the efficiency of targeted proteins renaturation gained upon their inclusion body forms interactions with chelated metal ions.
Subject(s)
Chromatography, Affinity/methods , Granulocyte Colony-Stimulating Factor/chemistry , Histidine/chemistry , Mercury/chemistry , Nickel/chemistry , Serine/chemistry , Chromatography, High Pressure Liquid/methods , Electrophoresis, Polyacrylamide Gel , Humans , Protein Folding , Recombinant ProteinsABSTRACT
A D-hydantoinase (5,6-dihydropyrimidine amidohydrolase) was purified to homogeneity from Bacillus circulans. Purification of two hundred forty-three-fold was achieved with an overall yield of 12%. The relative molecular mass of the native enzyme is 212,000 and that of the subunit is 53,000. This enzyme is an acidic protein with an isoelectric point of 4.55. The enzyme is sensitive to thiol reagent and requires metal ions for its activity. The optimal conditions for the hydantoinase activity are pH 8.0-10.0 and a temperature of 75 degrees C. The enzyme is the most stable in a pH range of 8.5-9.5 and up to 60 degrees C. The enzyme is significantly stable not only at high temperatures but also on treatment with protein denaturant SDS. These remarkable properties are used for the purification procedure.
Subject(s)
Amidohydrolases/isolation & purification , Bacillus/enzymology , Amidohydrolases/chemistry , Enzyme Inhibitors/chemistry , Enzyme Stability , Hydrogen-Ion Concentration , Metals/chemistry , Molecular Weight , Peptide Fragments/chemistry , Stereoisomerism , Substrate Specificity , TemperatureABSTRACT
In spite of the large diffusion of uterotonic drugs some doubts persist about which preparation and which dosage are the most suitable. For such a reason a group of pregnant women, to whom ergometrine maleate was administered at the delivery of the anterior shoulder of the fetus, was compared by the authors to an analogous group formed by pregnant women to whom oxytocin was administered under the same conditions. Pregnant women not submitted to a pharmacologic control of the third stage of labour served as a control group. Each study group was thereafter divided into 2 subgroups: the former is composed by patients submitted to episiotomy and the latter by patients not submitted to this procedure. Our results have shown the usefulness of both drugs in the active management of the third stage of labour, whereas different side effects may occur.
Subject(s)
Ergonovine/analogs & derivatives , Labor Stage, Third/drug effects , Labor, Obstetric/drug effects , Oxytocin/therapeutic use , Episiotomy , Ergonovine/therapeutic use , Female , Humans , Postpartum Hemorrhage/physiopathology , Pregnancy , Time FactorsABSTRACT
Lyme borreliosis acquired during pregnancy may be associated with stillbirth and fetal malformations. This paper reports preliminary results of a study intended to evaluate the frequency of Borrelia burgdorferi infection associated with spontaneous abortion in an endemic Italian area.
