scholarly journals Human β-adrenergic receptors. Simultaneous purification of β1- and β2-adrenergic-receptor peptides

1987 ◽  
Vol 248 (2) ◽  
pp. 557-566 ◽  
Author(s):  
S W Bahouth ◽  
C C Malbon

Beta-Adrenergic receptors from basal membranes of human placenta were purified from digitonin extracts by sequential rounds of affinity chromatography, hydrophobic chromatography, ion-exchange chromatography and steric-exclusion h.p.l.c. Basal membranes display both beta 1- and beta 2-adrenergic receptors, in the ratio 65:35. Affinity chromatography, hydrophobic chromatography on heptylamine-Sepharose and ion-exchange chromatography on DEAE-Sephacel removed most of the contaminating proteins, and final purification of the receptor to apparent homogeneity was achieved by steric-exclusion h.p.l.c. The purified receptors showed Mr 67000 on SDS/polyacrylamide-gel electrophoresis under reducing conditions. Specific binding of radioligand to the purified beta-adrenergic receptors displayed stereoselectivity, and the agonist competition profiles demonstrated the presence of both beta 1- and beta 2-receptors. By using the subtype-selective ligands CGP-20712A (beta 1-selective) and ICI-118,551 (beta 2-selective), the purified Mr-67000 species was shown to be composed of equivalent amounts of beta 1- and beta 2-adrenergic receptors. Affinity chromatography on Sepharose-alprenolol and sequential elution with 1 microM-CGP-20712A followed by 100 microM(-)-alprenolol permitted beta 1-adrenergic receptors to be resolved from the mixture of beta 1-/beta 2-adrenergic receptors. The pharmacologically distinct human beta 1 and beta 2-adrenergic receptors are shown to be structurally very similar peptides.

1987 ◽  
Vol 247 (1) ◽  
pp. 237-239 ◽  
Author(s):  
J Koivu ◽  
R Myllylä ◽  
K I Kivirikko

A two-step procedure is described for the purification of protein disulphide-isomerase (PDI). This procedure is based on the previous finding that the beta-subunit of the prolyl 4-hydroxylase tetramer (alpha 2 beta 2) is identical with PDI [Koivu, Myllylä, Helaakoski, Pihlajaniemi, Tasanen & Kivirikko (1987) J. Biol. Chem. 262, 6447-6449; Pihlajaniemi, Helaakoski, Tasanen, Myllylä, Huhtala, Koivu & Kivirikko (1987) EMBO J. 6, 643-649]. The procedure involves purification of the prolyl 4-hydroxylase tetramer by a simple affinity chromatography and subsequent isolation of the beta-subunit from the dissociated tetramer by ion-exchange chromatography.


OALib ◽  
2014 ◽  
Vol 01 (06) ◽  
pp. 1-5
Author(s):  
Mrigendra Rajput ◽  
Shimaa M. G. Mansour ◽  
Lyle J. Braun ◽  
Mahmoud Darweesh ◽  
Neelu Thakur ◽  
...  

Author(s):  
Angela Boxi ◽  
Isha Parikh ◽  
Radhika B S ◽  
Shryli K S

The present review is based on papers published between 1990 and 2020 and gives Comparative information about the most common protein purification techniques Gel-Filtration, Chromatography, Ion-Exchange Chromatography, Electrophoresis, Affinity Chromatography, and Dialysis, High-Pressure Liquid Chromatography. and their applications.


1991 ◽  
Vol 261 (4) ◽  
pp. H1135-H1140 ◽  
Author(s):  
R. Doshi ◽  
E. Strandness ◽  
D. Bernstein

During chronic hypoxemia, left ventricular beta-adrenergic receptor density is decreased and a dissociation occurs between increased chronotropic and decreased inotropic responses to chronically elevated sympathetic tone. To determine whether this dissociation was related to alterations in autonomic receptor populations in the right atrium, we studied right atrial cholinergic and beta-adrenergic receptors in chronically hypoxemic newborn lambs and in normoxemic controls. Heart rate response was determined by infusing isoproterenol at 0.1 or 0.5 microgram.kg-1.min-1. Muscarinic receptors were quantified with [3H]quinuclidinyl benzilate and beta-adrenergic receptors with [125I]iodocyanopindolol. Competition with ICI 118,551 was used to determine beta 1- vs. beta 2-receptor subtypes. In the hypoxemic lambs, isoproterenol resulted in a lesser percentage increase in heart rate (hypoxemic, 46 +/- 6% vs. control, 89 +/- 17%, P less than 0.05); however, because baseline heart rate was higher in the hypoxemic lambs (213 +/- 7 vs. 177 +/- 12 beats/min, P less than 0.05), maximal heart rate responses were similar (310 +/- 7 vs. 326 +/- 6 beats/min, NS). There was no change in receptor density or affinity of either muscarinic or beta-adrenergic receptors and no change in the proportion of beta 1- vs. beta 2-receptor subtypes. Thus the dissociation between the chronotropic and inotropic responses to chronic hypoxemia may be in part secondary to a differential regulation of beta-adrenergic receptors between the left ventricle and the right atrium.


1989 ◽  
Vol 256 (2) ◽  
pp. C310-C314 ◽  
Author(s):  
J. M. Madison ◽  
C. B. Basbaum ◽  
J. K. Brown ◽  
W. E. Finkbeiner

We characterized the beta-adrenergic receptors that mediate secretory responses to isoproterenol in cultured bovine tracheal submucosal gland cells. Previous studies have shown that these cells have morphological and biochemical features characteristic of serous cells. Isoproterenol, epinephrine, and norepinephrine each stimulated the secretion of 35SO4-labeled macromolecules from these cultured serous cells with a rank order of potency (isoproterenol greater than epinephrine greater than norepinephrine) consistent with the presence of beta 2-adrenergic receptors. These functional studies were supported by radioligand-binding studies using [I125]-iodocyanopindolol (125I-CYP) to identify beta-adrenergic receptors. 125I-CYP binding to membrane particulates prepared from cultured serous cells was saturable and of high affinity (equilibrium dissociation constant 20 +/- 3 pM; mean +/- SE, n = 6) and was antagonized stereoselectively by propranolol. Adrenergic agonists competed for 125I-CYP-binding sites with a rank order of potency characteristic of the beta 2-adrenergic receptor subtype. A specific beta 2-adrenergic receptor antagonist, ICI 118.551, competed for a single class of 125I-CYP-binding sites with high affinity (inhibition constant 1.8 +/- 0.3 nM, n = 3). We concluded that the secretory response of cultured tracheal gland cells to isoproterenol is a response mediated by beta-adrenergic receptors of the beta 2 subtype.


1991 ◽  
Vol 260 (5) ◽  
pp. R911-R915 ◽  
Author(s):  
N. Mori ◽  
N. Uozumi

Our recent study has revealed that catecholamines depress the endolymphatic sac direct current potential (ESP) by the beta-adrenergic action [Mori et al., Am. J. Physiol. 259 (regulatory Integrative Comp. Physiol. 28): R921-R924, 1990]. Beta-Adrenergic receptors have been subclassified into beta 1- and beta 2-receptors. Using beta 1-selective (dobutamine) and beta 2-selective (salbutamol) agonists and a beta 1-selective antagonist (atenolol), we determined the subtype of beta-adrenergic receptors that mediate the action of catecholamines on the ESP. Salbutamol depressed the ESP to a larger degree than dobutamine [34.0 +/- 2.6 (n = 7) vs. 13.0 +/- 2.0% (n = 8)] with a much lower dose (100 vs. 1,000 micrograms/kg). Atenolol failed to block the action of salbutamol on the ESP at a dose of 1 mg/kg, whereas propranolol inhibited it at the same dose. The results indicate that beta 2-receptors mediate the action of catecholamines on the ESP.


1981 ◽  
Vol 240 (4) ◽  
pp. E351-E357 ◽  
Author(s):  
J. A. Whitsett ◽  
M. A. Manton ◽  
C. Darovec-Beckerman ◽  
K. G. Adams ◽  
J. J. Moore

beta-Adrenergic receptors and catecholamine-sensitive adenylate cyclase were identified and partially characterized in membrane fractions of rabbit lungs from day 25 of gestation to adulthood with the beta-adrenergic antagonists (--)-[3H]dihydroalprenolol [(--)-[3H]DHA] and (--)-[125I]iodohydroxybenzylpindolol [(--)-[125I]HYP]. beta-Adrenergic receptor number (Bmax) increased 11.5-fold during this time period, increasing progressively during the latter days of gestation and the early neonatal period, from 37 +/- 10 fmol/mg protein at 25 days gestation to 425 +/- 51 fmol/mg in the adult rabbit lung (mean +/- SD). Receptor affinity for (--)-[3H]DHA (KD = 1.8 nM) or (--)-[125I]HYP (KD - 0.104 nM) and the proportion of beta 1- and beta 2-adrenergic receptor subtypes (60% beta 1 and 40% beta 2) did not change with advancing age. Basal adenylate cyclase activity in lung homogenates decreased significantly with increasing age, whereas the activity in the presence of catecholamine or NaF remained nearly constant. Catecholamines stimulated adenylate cyclase activity at all ages studied supporting a role of the maturation of beta-adrenergic receptors in the regulation of pulmonary function.


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