Isolation, characterization and opiate activity of β-endorphin from human pituitary glands

Li, Choh Hao; Chung, David; Doneen, Byron A.

doi:10.1016/s0006-291x(76)80189-1

Cited by 161 publications

(31 citation statements)

References 11 publications

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“…Both hyLPH (1) and h,3END (50)(51)(52) are found in the human pituitary, but the h,3END/hLPH molar ratio has been reported to be very low (53). Human ,fLPH is not degraded to hyLPH or "h,/MSH" during the process of blood collection, plasma separation, silicic acid extraction, and gel chromatography (11), and h/3LPH injected into normal human subjects is not converted to h,3END (26).…”

Section: Resultsmentioning

confidence: 99%

Simultaneous Assay of Immunoreactive β-Lipotropin, γ-Lipotropin, and β-Endorphin in Plasma of Normal Human Subjects, Patients with ACTH/Lipotropin Hypersecretory Syndromes, and Patients undergoing Chronic Hemodialysis

Bertagna¹,

Stone²,

Nicholson³

et al. 1981

J. Clin. Invest.

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Section: Resultsmentioning

confidence: 99%

Simultaneous Assay of Immunoreactive β-Lipotropin, γ-Lipotropin, and β-Endorphin in Plasma of Normal Human Subjects, Patients with ACTH/Lipotropin Hypersecretory Syndromes, and Patients undergoing Chronic Hemodialysis

Bertagna¹,

Stone²,

Nicholson³

et al. 1981

J. Clin. Invest.

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“…The discovery of enkephalins (1) has stimulated much interest in this class of opioid peptides. Several related peptides termed endorphins were later found in mammalian tissues (2)(3)(4)(5)(6)(7)(8). Although their physiological function is not yet known, these peptides are reported to possess opiatelike activity in many in vitro experiments (2-7).…”

mentioning

confidence: 99%

beta-Endorphin: formation of alpha-helix in lipid solutions.

Wu¹,

Lee²,

Loh³

et al. 1979

Proc. Natl. Acad. Sci. U.S.A.

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Human 8-endorphin adopts a partial helical conformation in aqueous solutions of cerebroside sulfate, ganglioside GMI, phosphatidylserine, and phosphatidic acid, but not of cerebroside and phosphatidylcholine, as evidenced by circular dichroic spectra. Addition of Ca2+ to the peptide in cerebroside sulfate solution can break up the helix; at. 10 mM Ca2+ the peptide (12 ,M) essentially exists in an unordered form.For comparison, sheep ,-lipotropin in acidic cerebroside sulfate solution (pH < 4) also has a partial helical -conformation, whereas human adrenocorticotropin does not. The conformation of the complex between human ,Bendorphin and lipids may be related to the opiatelike function of this peptide hormone. The opiate receptor has not yet been isolated and purified, but many studies have indicated that anionic groups at the receptor site are probably involved in the opiate receptor interactions and the prime mode is an electrostatic interaction between the protonated nitrogen of the opiates such as morphine and the anionic groups at the binding site. The discovery of enkephalins (1) has stimulated much interest in this class of opioid peptides. Several related peptides termed endorphins were later found in mammalian tissues (2-8). Although their physiological function is not yet known, these peptides are reported to possess opiatelike activity in many in vitro experiments (2-7). However,only O3-endorphins are analgesic in in vivo experiments (9, 10). The structure-function relationship dictates that these peptides bound to the, cell membrane must assume some ordered conformation to elicit their biological activities.The amino acid sequence of human f-endorphin is (5)Tyr-Gly-Gly-Phe-Met-Thr-Ser -Glu-Lys-Ser-Gln-Thr-Pro-Leu-Val -Thr-Leu-Phe-Lys-Asn-Ala-Ile -Ile -Lys-Asn-Ala-Tyr-Lys-Lys-Gly-Glu (Camel (3-endorphin has His-27 and Gln-31 instead of Tyr and Glu). The sequence of camel 3-endorphin is identical with the COOH-terminal 31 amino acid residues of sheep f3-lipotropin (11,12). Both 3-endorphin and (3-lipotropin in methanol or sodium dodecyl sulfate solution were previously shown to have a helical structure that can be as much as one-half of either peptide molecule (13). We report here on the conformation of f-endorphin in several lipid solutions. These lipids not only fulfill the requirement of the electrostatic interaction but also simulate a hydrophobic environment in the membrane that is conducive to the formation of ordered structure in the peptide molecule. MATERIAL AND METHODSHuman 3-endorphin and corticotropin (ACTH) were synthesized as described (10,14 was purified from an n-butanol solution (15). The cerebroside sulfate liposomes were prepared by suspending the lipid (1.5-2 mM) in water. The mixed micelles of lipid and C16E13.5 in water were prepared by drying the lipid from a chloroform solution under reduced pressure and dissolving it in the surfactant with a flash-mixer (15). For molar ratios less than 5, the phospholipids were solubilized at 500C, and the solution remained clear upon ...

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“…We previously reported the isolation, sequence determination, and synthesis of camel f3-endorphin (Ic-EP) (1,2) and human f3-endorphin (/3h-EP) (3,4) (see Fig. 1).…”

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confidence: 99%

Beta-Endorphin: dissociation of receptor binding activity from analgesic potency.

Li¹,

Tseng²,

Ferrara³

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

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We previously reported the isolation, sequence determination, and synthesis of camel f3-endorphin (Ic-EP) (1, 2) and human f3-endorphin (/3h-EP) (3, 4) (see Fig. 1 MATERIALS AND METHODSSynthetic ic-EP and 1h-EP were obtained as described, and [Gln8,Gly31]-3h-EP-Gly-Gly-NH2 were synthesized as described (9). The radioreceptor binding assay was performed according to the procedure recently described (7,8 presence of 2.5 ,uM 13h-EP. Triplicate determinations were performed with a variation of less than 7%. The analgesic activity was assessed in mice by the tail-flick method (11). Male ICR mice weighing 25-28 g were used (Simonsen Lab, Gilroy, CA). The peptide was dissolved in sterilized saline and injected intracerebroventricularly in a volume of S ul according to the method described (12). To evaluate the tail-flick response, a control latency (To) was obtained from the mean of two latency determinations. The To value was usually 1.5-2.5 sec. Mice with a control latency of more than 3 sec were not used for the study. The test latencies (T1) were determined at 5, 10, 20, 30, 60, 90, and 120 min after the injection of the peptide for each animal. Percent analgesia was calculated as [(T1-To)/(T2 -To)] X 100, in which the cut-off time (T2) was 7 sec. Mice were considered to be analgetic if the percent analgesia was 50% or more, observed at 10, 20, or 30 min after injection. Groups of at least eight mice were injected with different doses of the peptide. The median antinociceptive dose (AD50) and 95% confidence limits were computed as described (13) The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.

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Isolation, characterization and opiate activity of β-endorphin from human pituitary glands

Cited by 161 publications

References 11 publications

Simultaneous Assay of Immunoreactive β-Lipotropin, γ-Lipotropin, and β-Endorphin in Plasma of Normal Human Subjects, Patients with ACTH/Lipotropin Hypersecretory Syndromes, and Patients undergoing Chronic Hemodialysis

Simultaneous Assay of Immunoreactive β-Lipotropin, γ-Lipotropin, and β-Endorphin in Plasma of Normal Human Subjects, Patients with ACTH/Lipotropin Hypersecretory Syndromes, and Patients undergoing Chronic Hemodialysis

beta-Endorphin: formation of alpha-helix in lipid solutions.

Beta-Endorphin: dissociation of receptor binding activity from analgesic potency.

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