Binding of aflatoxins B1 and G1 to human serum proteins

Zusammenfassung In vitro Experimente mit¹⁴C-markiertem, gereinigtem Aflatoxin zur Untersuchung der Bindung von Aflatoxin B₁ und G₁ an verschiedene Serumproteine ergaben, dass Aflatoxin B₁ hauptsächlich mit-Globulin, G₁ dagegen vorwiegend mit Albumin bindet.

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This work was supported by part by a grant from the China Medical Board of New York, Inc., and was performed during one of us (S.S.L.) received a class C. research award from the National Science Council, Republic of China.     

Metabolism of aflatoxins B1 and G1 byAspergillus parasiticus

Résumé Un examen préliminaire fait avec une préparation d'Aspergillus parasiticus est rendu évidente la conversion de l'aflatoxine B en G. Il est probable que l'aflatoxines B₁ est le précurseur biogénétique d'autres aflatoxines produite par le champignon.

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K. K. M. is grateful to the Council of Scientific and Industrial Research, New Delhi, India, for the award of a Senior Research Fellowship.     

Binding of 3,3',5'-triiodo-L-thyronine (rT3) to human serum proteins]

The rT3-binding and human serum proteins was directly studied with tracer doses of radioactive rT3. Polyacrylamide gel electrophoresis showed 125I-rT3 added to human serum was distributed among two proteins: albumin (carrying 57% of tracer rT3) and TBPA )22%). No binding was observed to TBG, protein binding T4.     

Binding of tryptophan to different serum proteins in humans and in rats

Riassunto Sieri di uomo e di ratto sono stati incubati con C¹⁴-l-triptofano e sottoposti a elettroforesi su gel di poliacrilamide. Nel siero umano la radioattività si è localizzata nelle frazioni albuminica, prealbuminica e macroglobulinica. Nel siero di ratto il C¹⁴-l-triptofano si è localizzato nella zona delle albumine, -globuline e macroglobuline.     

Binding of centchroman--a nonsteroidal antifertility agent to human plasma proteins

Centchroman, a non-steroidal antifertility agent showed a low affinity (Kd = 13.19 X 10(-6) M) and nonsaturable binding to human plasma. Centchroman did not compete either with sex hormone binding globulin or corticosteroid binding globulin. Polyacrylamide gel electrophoresis and temperature dependent binding characteristics revealed that the protein responsible for centchroman binding to human plasma resembles albumin.     

Non-paramagnetism of human serum proteins

Zusammenfassung Normale Serumproteine wurden mittels Elektromagnetophorese in Zellulose-Azetatgel ausgeführt, wobei keine Trennung der einzelnen Proteine erfolgte. Es stellte sich heraus, dass Serumproteine keine paramagnetischen Eigenschaften aufweisen.     

Binding of centchroman—a nonsteroidal antifertility agent to human plasma proteins

Summary Centchroman, a non-steroidal antifertility agent showed a low affinity (K_d=13.19×10^–6 M) and nonsaturable binding to human plasma. Centchroman did not complete either with sex hormone binding globulin or corticosteroid binding globulin. Polyacrylamide gel electrophoresis and temperature dependent binding characteristics revealed that the protein responsible for centchroman binding to human plasma resembles albumin.Acknowledgment. The authors are grateful to Dr. Nitya Nand for his interest in this investigation. CDRI Communication No. 3333.     

Electrophoretic behavior of sonicated human serum proteins

Zusammenfassung Normale und abnorme Seren sowie gereinigtes menschliches Serumalbumin und Serumglobulin, wurden vor und nach Ultraschalleinwirkung auf elektrophoretisches Verhalten untersucht. Die Unterlagen deuten auf eine Bildung aussergewöhnlicher Komplexe zwischen gewissen Serumproteinen, wahrscheinlich-Globulin und Albuminfraktionen, durch ultrasonische Frequenzen hin.     

Binding of matrilysin-1 to human epithelial cells promotes its activity

Matrix metalloproteinase-7 (MMP-7, matrilysin- 1) modulates crucial biological events by processing many epithelial cell surface-associated effectors. We addressed MMP-7 interaction with human epithelial cells and its resulting activity. In human endometrium, a model of controlled tissue remodeling, proMMP-7 was diffusely immunolocalized inside epithelial cells, whereas MMP-7 delineated their entire plasma membrane. Endometrial explants preferentially retained active MMP-7, but not proMMP-7. Endometrial epithelial cells and carcinoma cells from various tissues bound active MMP-7. Endometrial carcinoma-derived Ishikawa cells showed high affinity (K_D of ~2.5 nM) and capacity (~260 000 sites per cell) for MMP-7. MMP-7 binding decreased by extracting membrane sterols or interfering with heparan sulfate proteoglycans, and was abrogated by tissue inhibitors of metalloproteinase-2 (TIMP-2) or synthetic MMP inhibitors. Bound MMP-7 not only remained fully active towards a macromolecular substrate but also became resistant to TIMP-2. We conclude that MMP-7-selective targeting to the plasma membrane of epithelial cells promotes its activity by conferring resistance to TIMP-2. A. Berton, C. Selvais: These authors contributed equally to this work. P. J. Courtoy, E. Marbaix, H. Emonard: These authors contributed equally to the supervision of this work. Received 20 September 2006; received after revision 30 November 2006; accepted 18 January 2007     

Paramagnetism of human serum proteins demonstrated by two-stage electromagnetophoresis

Zusammenfassung Normale Serumproteine wurden mittels zweistufiger Elektromagnetophorese in Polyacrylamidgel, einer neuen Technik, aufgetrennt, wobei die Trennung auf Grund der paramagnetischen Eigenschaften der einzelnen Proteine erfolgt.

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Supported by William Beaumont Hospital Research Institute in Affiliation with the Research Laboratories, General Motors Corporation and Department of Pathology, School of Medicine, Wayne State University.     

Binding of I-131 labeled thyroxine by water soluble human pituitary proteins

Résumé Etude de la propriété qu'ont les protéines pituitaires solubles dans l'eau de lier la thyroxine d'indice I-131. L'électrophorèse au pH 8,6, en utilisant comme tampons le véronal et le tris-maléate, de même que l'autoradiographie sur bandes de papier montrent que ces protéines lient la thyroxine I-131 dans une zone correspondant à la fraction des globulines du sérum humain.     

Proposition of a reference serum for the immunochemical assay of human serum proteins]

Sera of healthy students (from Academy of Paris) aged between 18 and 30 years were collected with a view to routine clinical testing. 50 samples each representing the pooled sera of 400 individuals were investigated by evaluating 7 proteins for each pooled sample. Calculations of standard deviations showed that there existed a significant reproductibility of less than 2% for the population as a whole. These pooled sera representing 20 000 individual blood samples are proposed as a standard of human serum proteins.