Ligand specificity of progesterone-binding proteins in guinea pig and sheep

Kontula, Kimmo; Jänne, Olli A.; Rajakoski, E.; Tanhuanpää, Eero; Vihko, R.

doi:10.1016/0022-4731(74)90026-0

Cited by 27 publications

(4 citation statements)

References 13 publications

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“…The existence of high affinity progesterone-binding proteins in the myometrium of different mammalian species has been reported by several investigators (Milgrom et al 1970(Milgrom et al , 1972Wiest 8c Rao 1971;Corvol et al 1972;Faber et al 1912aFaber et al ,b, 1973Feil et al 1972;Kontula et al 1972Kontula et al , 1973Kontula et al , 1974Kontula et al , 1975McGuire 8c Bariso 1972;Philibert 8c Raynaud 1973Rao et al 1973). However, only scanty and conflicting information is available about the possible presence of these binding proteins, commonly referred to as "receptors", in the endo¬ metrial compartment of mammalian uteri.…”

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confidence: 81%

“…Plasma was prepared by low speed centrifugation of blood. Determination of the intrinsic association constants and the number of binding sites The intrinsic association constants and the number of binding sites were determined as previously described (Kontula et al 1974). The binding data were plotted according to Scatchard (1949).…”

Section: Preparation Of the Endometrial And Myometrial Cytosolsmentioning

confidence: 99%

“…Sheep was chosen as a test animal because of the close similarity in the properties of the progesterone receptors isolated from sheep and human myometrium (Kontula et al 1973(Kontula et al , 1974(Kontula et al , 1975 Jänne et al, in press).…”

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confidence: 99%

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Progesterone-Binding Proteins From Endometrium and Myometrium of Sheep Uterus: A Comparative Study

Kontula

1975

Acta Endocrinologica

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The binding of tritiated progesterone to the cytoplasmic progestogen receptors from oestrogen-primed sheep endometrium and myometrium has been investigated. The binding characteristics of the progesterone receptors from both sources were determined in the supernatant fractions obtained after high speed centrifugation of the myometrial and endometrial homogenates. High affinity binding proteins with identical association constants for progesterone (1 \m=x\ 109 m\m=-\1) were detected in both endometrium and myometrium. The concentration of binding sites was also of the same order of magnitude in both tissues. After centrifugation on sucrose gradients, these binding proteins were shown to have similar sedimentation constants, 7 S in a gradient containing no added KC1 and 4 S in a gradient containing 0.4 m KCI. The binding peaks from both sources could be abolished by heating the cytosol at 60\s=deg\Cfor half an hour. The proteinaceous nature of the binding materials was demonstrated by incubation of the endometrial and myometrial cytosols with pronase, DNase and RNase: the binding was totally eliminated by the proteolytic action of pronase whereas DNase and RNase had no effect.The ligand specificity of the two progesterone binding proteins was studied using a competitive protein-binding technique. Both the endometrial and the myometrial receptor proteins were shown to bind only steroids which are known potent progestogens. In addition, the relative affinities of the binding proteins for 37 steroidal compounds closely resembled each other. Thus, the physicochemical and binding data obtained show that a very close similarity exists between the progesterone-binding proteins in the endometrium and myometrium of ovariectomized sheep after oestradiol treatment.

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confidence: 81%

Section: Preparation Of the Endometrial And Myometrial Cytosolsmentioning

confidence: 99%

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Progesterone-Binding Proteins From Endometrium and Myometrium of Sheep Uterus: A Comparative Study

Kontula

1975

Acta Endocrinologica

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“…A sedimentation coefficient of 6-7 S or 4-5 S has been determined in density gradient buffer. The 6-7 S receptor is characterized by a highly specific affinity for progesterone (Kontula et al 1973(Kontula et al , 1974. However, some species differences have been revealed (Kontula et al 1974 b;Kontula et al 1975).…”

Section: Binding and Activitymentioning

confidence: 96%