The effect of protamine on the action of ACTH

Zusammenfassung Bei Ratten verursachen 0,5µg ACTH/100 g keine Verminderung des Ascorbinsäuregehaltes der Nebenniere, wenn gleichzeitig 20 mg/kg Protaminsulfat gegeben werden.Ebenfalls bei Ratten vermag ACTH bei gleichzeitiger Verabreichung mit Protaminsulfat keine Thymusatrophie hervorzurufen. Die Beeinflussung der Chromatophoren-Aktivität durch dasselbe ACTH-Präparat beiRana esculenta wird dagegen durch Protaminsulfat nicht geändert.     

The interaction of protamine with human blood plasma proteins

Zusammenfassung Es wurden Interaktionen von Protamin mit vorher in Agar-Gel elektrophoretisch getrennten plasmatischen Eiweisskörpern untersucht. Neben der schon früher bekannten Interaktion mit Fibrinogen wurden auch solche mit beiden Klassen der plasmatischen Lipoproteine gefunden.     

Aberrant protamine 1/protamine 2 ratios in sperm of infertile human males

Protamines were extracted from the sperm of fertile and infertile human males and the relative proportion of protamines 1, 2, and 3 were determined by scanning microdensitometry following electrophoresis of total protamine in polyacrylamide gels. The proportion of the three protamines was found to be similar in sperm obtained from different normal males. The distribution of protamines in sperm obtained from a select group of infertile males producing an elevated level of large sperm heads, in contrast, was different from that of the fertile males.     

Aberrant protamine 1/protamine 2 ratios in sperm of infertile human males

Summary Protamines were extracted from the sperm of fertile and infertile human males and the relative proportion of protamines 1, 2, and 3 were determined by scanning microdensitometry following electrophoresis of total protamine in polyacrylamide gels. The proportion of the three protamines was found to be similar in sperm obtained from different normal males. The distribution of protamines in sperm obtained from a select group of infertile males producing an elevated level of large sperm heads, in contrast, was different from that of the fertile males.     

Structural changes of deoxyribonucleoprotein fibres following gamma-irradiation under aerobic and hypoxic conditions.

The DNP fibres gamma-irradiated under aerobic condition showed a reduction of their diameter, while no remarkable changes were observed in the DNP fibres irradiated under hypoxic condition by scanning electron microscopy.     

The extractibility of calf thymus histone fractions

Zusammenfassung Bei der Extraktion von Zellkernen mit Hilfe verdünnter Salzsäure ändert sich die Zusammensetzung einzelner Extrakte in Abhängigkeit von der Konzentration der benutzten Säure. Die Fraktion des Kalbsthymushistons, die an Arginin und Tyrosin reich ist, scheint an die Desoxyribonukleinsäure des Zellkernes fester gebunden zu sein als die zweite, an Tyrosin arme und an Lysin reiche Fraktion.     

The kinetics of estrogen binding to rat alpha-fetoprotein

Fluid obtained from rat fetuses was utilized to characterize the affinity, number of binding sites, and the association and dissociation rate kinetics of the binding of estradiol and estrone to AFP. Statistical analysis demonstrated no differences when the values for the AFP-estradiol interaction were compared with those obtained for the ATP-estrone interaction. These data demonstrate that rat AFP specifically binds estradiol and estrone with a high capacity, high affinity, and similar binding kinetics.     

The binding of cardiac glycosides to bull spermatozoa

Resumen Se ha investigado la unión de glicósidos cardiacos al espermatozoide de toro. Dicha unión es sensible a inhibidores metabólicos y fué localizada en la membrana celular del segmento intermediario y la cola.     

The kinetics of estrogen binding to rat α-fetoprotein

Summary Fluid obtained from rat fetuses was utilized to characterize the affinity, number of binding sites, and the association and dissociation rate kinetics of the binding of estradiol and estrone to AFP. Statistical analysis demonstrated no differences when the values for the AFP-estradiol interaction were compared with those obtained for the AFP-estrone interaction. These data demonstrate that rat AFP specifically binds estradiol and estrone with a high capacity, high affinity, and similar binding kinetics.This work was supported by NSF grant PCM-8109847 and by a Grant-in-Aid of Research from Sigma Xi, The Scientific Research Society.     

The binding of some sodium substitutes to chondroitin sulfate

Résumé Il arrive souvent que l'on doive substituer l'ion de sodium dans les solutions physiologiques. Un effet particulier en est la compétition du substitut vis-à-vis les ions de sodium liés au sulfate de chondroitine. Nous démontrons que le sucrose ne déplace pas cette portion du sodium lié, alors que les ions de lithium et de choline possèdent une grande affinité pour ces sites de liaison, affinité moindre cependant que celle de l'ion de calcium. Les conséquences physiologiques qui en ressortent sont discutées.     

The specificity of binding of glycoprotein hormones to their receptors

The glycoprotein hormone receptor family is peculiar because, in contrast to other G protein-coupled receptors, a large N-terminal extracellular ectodomain is responsible for hormone recognition. Hormone-receptor pairs have evolved in such a manner that a limited number of positions both at the 'seat-belt' domain of the hormone and the leucine-rich repeats of the receptor, play attractive and repulsive interactions for binding and specificity, respectively. Surprisingly, the constitutive activity of the receptor, mostly modulated by highly conserved amino acids within the heptahelical domain of the receptor (i.e., outside the hormone binding region), also regulates effectiveness of hormone recognition by the extracellular part. In this review we analyze, at the molecular level, these important discriminating determinants for selective binding of glycoprotein hormones to their receptors, as well as natural mutations, observed in patients with gestational hyperthyroidism or ovarian hyperstimulation syndrome, that modify the selectivity of binding.     

The binding of FITC-insulin to ANAE-positive cells in rat thymus

Summary To determine if thymic macrophages have insulin receptors, alternate sections of rat thymus were stained with FITC-insulin and examined for nonspecific esterase (ANAE) activity. Cells showing a diffuse ANAE staining pattern also bound FITC-insulin. These cells were concentrated in the cortico-medullary border and increased in number following administration of cortisol. Thymic macrophages may be insulin-dependent and therefore could be malfunctional in diabetes.     

The binding of tritiated dexamethasone to lymphocytes of normal and leukemic subjects]

Specific binding sites for 3H-dexamethasone, possessing the characteristics of glucocorticoid receptors, were demonstrated in normal human circulating lymphocytes. The number of glucocorticoid receptors was found different from normal in half of the acute or chronic lymphoid leukaemias studied. A correlation between the number of glucocorticoid receptors and the therapeutical benefit of the glucocorticoid administration will be performed, including these preliminary observations.     

The binding of FITC-insulin to ANAE-positive cells in rat thymus

To determine if thymic macrophages have insulin receptors, alternate sections of rat thymus were stained with FITC-insulin and examined for nonspecific esterase (ANAE) activity. Cells showing a diffuse ANAE staining pattern also bound FITC-insulin. These cells were concentrated in the cortico-medullary border and increased in number following administration of cortisol. Thymic macrophages may be insulin-dependent and therefore could be malfunctional in diabetes.