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Biomedical subjects

J Spiess

Publications and source records attributed to J Spiess.

At least 109 records · Page 6Linked to original sources

Phosphorylation of high mobility group 14 protein by cyclic nucleotide-dependent protein kinases.

Chromosomal high mobility group (HMG) proteins have been examined as substrates for cGMP-dependent and cAMP-dependent protein kinases. Of the four HMG proteins only HMG 14 contained a major high affinity site which could be phosphorylated by both enzymes, preferentially by cGMP-dependent protein kinase. One mol of 32P was incorporated/mol of HMG 14. Kinetic analysis revealed apparent Km and Vmax of 40.5 microM and 14.7 mumol/min/mg, respectively, for cGMP-dependent protein kinase, and 123 microM and 11.1 mumol/min/mg, respectively, for cAMP-dependent protein kinase. Tryptic maps of 32P-labeled phosphopeptides of HMG 14 demonstrated phosphorylation of the same site by both enzymes. The tryptic fragment containing the major phosphorylation site was identified by amino acid composition and sequence as HMG 14 (residues 4-13): H-Lys-Val-Ser(P)-Ser-Ala-Glu-Gly-Ala-Ala-Lys-OH. HMG 14 and HMG 17 also contained minor sites which could be phosphorylated by cGMP-dependent protein kinase. Tryptic phosphopeptides mapping suggested that the same minor site was phosphorylated on both HMG 14 and 17. On the basis of amino acid composition, the tryptic peptides carrying the minor phosphorylation sites were identified as H-Leu-Ser(P)-Ala-Lys representing residues 23-26 and 27-30 of HMG 14 and HMG 17, respectively.

Amino Acids↗

Corticotropin-releasing factor: effects on the sympathetic nervous system and oxygen consumption.

Corticotropin-releasing factor administered intracerebroventricularly produces prolonged elevation of plasma concentration of epinephrine, norepinephrine and glucose. These hormonal changes are associated with an increase in motor activity and oxygen consumption. No change in body temperature is observed. CRF produces changes in animal physiology that are similar to those observed in response to stress.

Animals↗

Comparison of the biologic actions of corticotropin-releasing factor and sauvagine.

Corticotropin-releasing factor (CRF), a peptide isolated from ovine hypothalamus, and sauvagine, a peptide isolated from frog skin, share significant structural homology and elicit a number of similar biological responses. CRF is more potent than sauvagine in stimulating pituitary ACTH secretion. Sauvagine, however, is 5-10 times more potent than CRF to act within the brain to increase plasma levels of catecholamines and glucose and to elevate mean arterial pressure. Sauvagine is likewise more potent than CRF to act outside the brain to increase superior mesenteric artery flow and plasma glucose concentrations and to decrease mean arterial pressure. CRF and sauvagine produce important effects representative of biologically active peptides.

Adrenocorticotropic Hormone↗

NH2-terminal amino acid sequence and peptide mapping of purified human beta-lipotropin: comparison with previously proposed sequences.

Beta-Lipotropin was purified from human pituitary glands to a purity of greater than 90%. The amino acid compositions of beta-lipotropin and its three cyanogen bromide cleavage peptide fragments were in agreement with the structure proposed by Li and Chung [Li, C.H. & Chung, D. (1981) Int. J. Pept. Protein Res. 17, 131-142]. However, the amino acid sequence of its NH2-terminal 46 amino acid residues established here differs both from the sequence derived from the direct sequence analysis of the peptide reported by Li and Chung and from that predicted on the basis of the nucleotide sequence of the human pro-opiolipomelanocortin gene proposed by Chang et al. [Chang, A.C.Y., Cochet, M. & Cohen, S.W. (1980) Proc. Natl. Acad. Sci. USA 77,4890-4894] but agrees with the structure recently derived by direct sequence analysis by Hsi et al. [Hsi, K.L., Seidah, N.G., Lu, C.L. & Chrétien, M. (1981) Biochem. Biophys. Res. Commun. 103, 1329-1335] and predicted on the basis of nucleotide sequence analysis by Takahashi et al. [Takahashi, H., Teranishi, Y., Nakanishi, S. & Numa, S. (1981) FEBS Lett. 135, 97-102]. These discrepancies, found from residues 9 to 25 of beta-lipotropin, could result from pro-opiolipomelanocortin gene polymorphism, from the existence of multiple genes for pro-opiolipomelanocortin, or, more probably, from minor errors in nucleotide and amino acid sequence analyses.

Amino Acid Sequence↗

In vivo corticotropin-releasing factor-induced secretion of adrenocorticotropin, beta-endorphin, and corticosterone.

A 41-residue peptide purified as a corticotropin-releasing factor/beta-endorphin-releasing factor (CRF) in vitro was tested for its ability to stimulate the secretion of ACTH, beta-endorphin, and corticosterone in three animal groups: 1) unanesthesized rats bearing indwelling venous cannulae, 2) rats pretreated with chloropromazine plus morphine sulfate plus pentobarbital (CPZ-MS-Nb, and 3) rats with hypothalamic deafferentiations in the frontal and lateral retrochiasmatic areas. In all three bioassays iv administration of 0.1-10 micrograms CRF elicited a dose-related increase in plasma ACTH and beta-endorphin values over a 5- to 15-min period. Corticosterone secretion was also elevated but responded maximally with all doses of CRF tested. Pretreatment of CPZ-MS-Nb animals with 20 micrograms dexamethasone 4 h before assay abolished the CRF-induced hormone secretion. These data suggest that CRF may play a physiological role in the regulation of the hypothalamic-pituitary-adrenal axis.

Adrenocorticotropic Hormone↗

Corticotropin-releasing factor: actions on the sympathetic nervous system and metabolism.

Corticotropin-releasing factor (CRF) injected into the brains of rats produces hyperglycemia and an increase in plasma concentrations of glucagon, epinephrine, and norepinephrine. Neither hypophysectomy nor adrenalectomy prevents CRF-induced hyperglycemia. However, a role of adrenal epinephrine release in mediating CRF-induced hyperglycemia is supported by the finding that the central nervous system-selective somatostatin analog, desAA1,2,4,5,12,13-[D-Trp8]somatostatin, totally prevents the elevation of plasma epinephrine and suppresses the rise of plasma glucose but does not alter the increase in plasma norepinephrine induced by CRF. Pretreatment with the ganglionic blocker chlorisondamine completely prevents the CRF-induced rises in plasma glucose, epinephrine, and norepinephrine. These results demonstrate that CRF acts within the brain to stimulate sympathetic outflow, which results in the development of hyperglycemia. In contrast to other peptides that act within the central nervous system, e.g. bombesin, TRF, and beta-endorphin, whose hyperglycemic actions depend exclusively on adrenal epinephrine secretion, CRF-induced hyperglycemia is secondary to the enhanced secretion of both epinephrine and norepinephrine.

Animals↗

Pituitary microadenomas causing Cushing's disease respond to corticotropin-releasing factor.

Corticotropin-releasing factor (CRF) was administered as an iv bolus to two young women with mild Cushing's disease shortly before and one week after successful transsphenoidal microadenomectomy. The dose of CRF (1 microgram/kg body weight) had previously been shown to stimulate increased plasma ACTH and cortisol in normal subjects. In the first patient, prior to surgery, there were brisk increases in ACTH and cortisol that exceeded those observed in normal subjects. ACTH rose by 2 min and reached a peak between 15-30 min. Cortisol increased by 10 min and peaked between 45-60 min. After surgery, at a time when plasma cortisol was maintained at similar levels with exogenous hydrocortisone, there was no plasma ACTH or LH, TSH and prolactin increased after administration of LRH and TRH, and GH increased in response to insulin-induced hypoglycemia. The second patient had higher basal plasma ACTH and cortisol than the first patient. CRF-induced increments in ACTH and cortisol were much less, but the time course was similar and peak levels attained were still higher than those in normal subjects. After surgery, at a time when plasma cortisol was maintained at a much lower level with exogenous hydrocortisone, there was no plasma ACTH or cortisol response. She had mild, transient diabetes insipidus. Basal levels of all other anterior pituitary hormones were normal. These results demonstrate that two microadenomas causing Cushing's disease were responsive to CRF in situ and suggest that CRF may be involved in the etiology and/or the responses to changes in plasma glucocorticoid concentrations observed in patients with Cushing's disease.

Adenoma↗

Isolation and sequence analysis of a somatostatin-like polypeptide from ovine hypothalamus.

A large somatostatin-like polypeptide of apparent molecular weight 3000-4500 [4K somatostatin (SS)] was isolated from ovine hypothalamus. The polypeptide was obtained in the methionine sulfoxide form. Two microsequence analyses of 0.6 and 1.8 nmol of 4K SS were performed with a modified 890 C spinning cup sequencer. The sequencing data together with results of amino acid analysis and C-terminal end-group determination indicated that 4K SS was identical with somatostatin-28 (SS-28) isolated from procine upper small intestine and sequenced by Pradayrol et al. [Pradayrol, L., Jörnvall, H., Mutt, V., & Ribet, A. (1980) FEBS Lett. 109, 55-58]. No free cysteine sulfhydryl group could be detected, so that it was assumed that the two cysteine residues of ovine SS-28 formed an intramolecular disulfide bond. Besides the structure of SS-28, the N-terminal first 30 residues of an unknown polypeptide from ovine hypothalamus were sequenced as follows: H-Ile-Pro-Ile-Tyr-Glu-Lys-Lys-Tyr-Gly-Gln-Val-Pro-Met-Cys-Asp-Ala-Gly-Glu-Gln- Cys-Ala-Val-Arg-Lys-Gly-Ala-Arg-Ile-Gly-Lys. Trypsin cleaved the somatostatin (SS) entity less selectively from ovine hypothalamic SS-28 than from rat hypothalamic 12 000-dalton SS-like polypeptide (12K SS). Native ovine hypothalamic SS-28 was found to be highly potent in inhibit growth hormone release from cultured rat anterior pituitary cells. The results raised doubts that ovine SS-28 would be an SS precursor and indicated that SS-28 itself may possess regulatory functions.

Amino Acid Sequence↗

Primary structure of corticotropin-releasing factor from ovine hypothalamus.

Sequence analysis was performed of an ovine hypothalamic 41-residue polypeptide that had been postulated to be a putative corticotropin-releasing factor (CRF) because of its high intrinsic corticotropin releasing activity. The NH2-terminal 39 residues of CRF were determined by Edman degradation of 0.6-3.5 nmol of peptide in a Wittmann-Liebold modified Beckman 890C spinning cup sequencer with reverse-phase high-pressure liquid chromatography for the identification of amino acid phenylthiohydantoins (direct micro-sequence analysis). Evidence for residue 40 (isoleucine) was provided by direct micro-sequence analysis of 2.0 nmol of acetylated CRF selectively cleaved at its arginine residues by trypsin prior to analysis. The thermolytic COOH-terminal fragment isoleucyl-alanineamide was characterized as its dansyl derivative. Based on the analytical data, the following primary structure is proposed for ovine hypothalamic CRF: H-Ser-Gln-Glu-Pro-Pro-Ile-Ser-Leu-Asp-Leu-Thr-Phe-His-Leu-Leu-Arg-Glu-Val-Leu-Glu-Met-Thr-Lys-Ala-Asp-Gln-Leu-Ala-Gln-Gln-Ala-His-Ser-Asn-Arg-Lys-Leu-Leu-Asp -Ile-Ala-NH2. In agreement with this proposal, the synthetic replicate of CRF is highly potent in stimulating secretion of both corticotropin and beta-endorphin-like immunoactivities.

Adrenocorticotropic Hormone↗

Isolation and characterization of somatostatin from pigeon pancreas.

Most of the somatostatin-like activity from pigeon pancreas was found to correspond to small species with an apparent molecular weight of 1500--2500. This species was isolated under conditions minimizing intermolecular interactions and protease activities. The isolated product was characterized by two somatostatin radioimmunoassays, a bioassay, endgroup determination, and amino acid analysis. The structure of the isolated compound was determined to be H-Ala-Gly-cyclo-(Cys-Lys-Asn-Phe-Phe-Trp-Lys-Thr-Phe-Thr-Ser-Cys)-OH. Additionally, small amounts of des-Ala1-somatostatin, a possible degradation product of pancreatic somatostatin, and a large somatostatin-like species with an apparent molecular weight of 11,000--12,500 were detected. It is concluded that the main somatostatin-like polypeptide isolated from pigeon pancreas is identical to the mammalian hypothalamic tetradecapeptide somatostatin.

Amino Acid Sequence↗

Immunotherapy in bee sting hypersensitivity. Bee venom versus wholebody extract.

Fifty-six patients with serologically confirmed bee sting hypersensitivity were treated for 1-3 years with either bee venom (BV) (31 patients) or wholebody extract (WBE) (25 per cent of re-exposed patients on BV-therapy showed a diminished reaction and 75% no reaction. Thirty-three per cent of re-exposed patients on WBE-therapy developed an unchanged or worse reaction, 42% a diminished reaction and 25% no reaction at all. An initial rise in BV-specific IgE was observed in BV-treated patients, whereas IgE levels after 1 year of treatment lay significantly below pretreatment values in both treatment groups. BV-specific IgG increased markedly in patients on BV-therapy and decreased slightly in those on WBE-therapy. The initial IgE increase induced by BV-therapy was insignificant in patients with high pretreatment levels of specific IgG-antibodies. Similarly, re-exposed patients with high BV-specific IgG showed no IgE increase, whereas a substantial rise in specific IgE was observed in those with low IgG. On the basis of clinical and serological results immunotherapy with BV is considered to be clearly superior to immunotherpy with WBE.

Adult↗

Isolation and characterization of somatostatin from anglerfish pancreatic islet.

Somatostatin was purified from anglerfish pancreatic islets using acetic acid extraction, gel filtration (Bio-Gel P-10), ion exchange chromatography (CM Bio-Gel A), and reversed phase high pressure liquid chromatography. The resulting peptide was characterized by RIA, bioassay, and determination of amino acid composition. Anglerfish islet somatostatin was found to possess an amino acid composition and immunological and biological activities equivalent to synthetic somatostatin. Sequence analyses revealed that the primary structure was H-Ala-Gly-cyclo-[Cys-Lys-Asn-Phe-Phe-Trp-Lys-Thr-Phe-Thr-Ser-Cys]-OH. These results demonstrate that anglerfish islet somatostatin has the same primary structure as somatostatin from all other sources characterized to date.

Amino Acid Sequence↗