H. M. S. “Victory.”

Fraser, Edward

doi:10.1080/00253359.1922.10655122

Cited by 4 publications

(4 citation statements)

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“…In addition TRH antibody was generously donated by Dr Hamish Fraser (Edinburgh University). Some specificity characteristics of these antibodies have been described [3,9] and further data relevant to the rat sequences are presented below.…”

Section: Antibodies To Trh Und Gip-his-pro-gly-lysmentioning

confidence: 99%

Specific processing of the thyrotropin-releasing prohormone in rat brain and spinal cord

Cockle

Smyth

1987

Eur J Biochem

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Thyrotropin-releasing hormone (TRH) and TRH extended peptides were extracted from rat hypothalamus and spinal cord and resolved by gel exclusion chromatography under dissociating conditions. Peptides related to TRH were detected by trypsin digestion and radioimmunoassay with an antibody to TRH or an antibody raised against the pentapeptide Glp-His-Pro-Gly-Lys. In addition to the tripeptide hormone a series of C-terminally extended forms of TRH was shown to occur in both tissues; no N-terminally extended peptides were detected. The structure of the TRH-related peptides was confirmed by chromatographic identification of the N-terminal pentapeptide sequence released by trypsin.The TRH extended peptides, which accounted for 15-20% of the total TRH, were present in three groups of different molecular size corresponding to predicted fragments of the TRH prohormone. One of the peptides in the spinal cord was identified by chromatographic comparison with a synthetic 16-residue peptide representing residues 154-169 of the prohormone. In the spinal cord the TRH extended peptides differed in their relative concentrations from the corresponding peptides in the hypothalamus, possibly reflecting differences in processing. The finding of extended forms of TRH in which the extension occurs only on the C-terminal side of the hormone sequence shows that the prohormone undergoes highly specific processing.The prohormone of thyrotropin-releasing hormone (TRH) has been shown to contain multiple copies of the TRH sequence Gln-His-Pro-Gly, enclosed by pairs of consecutive basic residues and separated by intervening sequences [I, 21. By analogy with other gene-duplicated prohormones, the proteolytic processing of the TRH prohormone would be expected to take place primarily at paired basic residues sequences but the processing reactions would not be expected to go to completion. It was anticipated, therefore, that Nterminally and C-terminally extended forms of TRH would occur naturally. In previous studies we have described the preparation of an antibody to a synthetic pentapeptide which could be used to identify extended forms of TRH [3] and we were able to demonstrate their existence in Xenopus skin and bovine hypothalamus [4]. In this communication we present the results of an investigation of TRH-related peptides in the rat which reveal a striking specificity in the TRH processing in the hypothalamus and spinal cord. EXPERIMENTAL PROCEDURE tional fluorenylmethoxycarbonyl methodology [5].The imidazole group of histidine was protected by the butyloxycarbonyl substituent, the gudnidino group of arginine by the methoxytrimethylbenzene-sulphonyl substituent, the hydroxyl group of threonine and serine and the 8-and y-carboxyl groups of aspartic and glutamic acids by the t-butyl substituent. Coupling in the presence of 1-hydroxybenztriazole was effected by reaction of the pentafluorophenyl ester of the fluorenylmethoxycarbonyl-amino acids, with the exception of threonine and serine, which were used as the oxobenztriazine esters, and argini...

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Section: Antibodies To Trh Und Gip-his-pro-gly-lysmentioning

confidence: 99%

Specific processing of the thyrotropin-releasing prohormone in rat brain and spinal cord

Cockle

Smyth

1987

Eur J Biochem

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“…In the first study [16] we applied the theory of learning through variation (see, for example, Fraser and Linder [17], Linder et al [18]) to the re-design of the original distillation simulation mentioned above. This study involved narrowing the scope of the simulation in an attempt to bring critical aspects of distillation into focal awareness for the students.…”

Section: Introductionmentioning

confidence: 99%

Enhancing the Learning of Fluid Mechanics Using Computer Simulations

Fraser

Pillay²,

Tjatindi³

et al. 2007

J of Engineering Edu

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This paper reports the results of a study into the impact of computer simulations on the understanding of fluid mechanics by engineering students. A "lesson study" approach was taken, using constructivist educational theory combined with the variation theory of learning from phenomenography to inform the design of learning activities and to assess their impact. Student difficulties with fluid mechanics concepts were assessed using questions from the Fluid Mechanics Concept Inventory (FMCI). Students had the greatest difficulties with pressure measurement, fluid flow through pipes with changing diameter, and velocity profiles for fluid between flat plates. We developed a set of three simulations to address these difficulties. The impact of the simulations was gauged by a second administration of the FMCI. Most of the students in the sophomore fluid mechanics class participated in the whole of this exercise. Students showed significant improvement in two of the three areas of difficulty. Student feedback on this as an additional learning exercise was very positive.

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“…The TRH-specific antibody exhibited a high specificity for the 5-oxoprolyl residue at the N-terminus and the amide group at the C-terminus of TRH and TRH-like peptides but was less stringent with respect to the amino acid at position 2 [9]. The synthetic tetrapeptide Glp-Glu-Pro-Trp exhibited a very low affinity for the TRH-specific antibody.…”

Section: Ria Proceduresmentioning

confidence: 98%

Isolation and identification of N‐terminally extended forms of 5‐oxoprolylglutamylprolinamide (Glp‐Glu‐Pro‐NH₂), a thyrotropin‐releasing‐hormone(TRH)‐like peptide present in human semen

Khan

Smyth

1993

European Journal of Biochemistry

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N-terminally extended forms of 5-oxoprolylglutamylprolinamide (Glp-Glu-Pro-NH,), a thyrotropin-releasing-hormone(TRH)-like peptide associated with the male reproductive system, were isolated from human semen by gel exclusion on Sephadex G50, ion-exchange chromatography on SPSephade C25 and QAE-Sephadex A25, and by HPLC. The peptides were located by trypsin-catalysed release of their C-terminal fragments which were detected by RIA with a TRH-specific antibody. A series of overlapping peptides containing 16,18, 22 and 25 residues was obtained in homogeneous form and their sequences were determined by automatic Edman degradation. The peptides all terminated in -Lys-Gln-Glu-Pro-NH, and were found to correspond to sequences occurring between residues 350-374 of semenogelin, a protein present in human semen. In semenogelin, however, the Gln-Glu-Pro sequence is followed by tryptophan and not glycine which is normally essential for formation of the C-terminal amide group. Model experiments with the synthetic peptide Glp-Glu-Pro-Trp showed that under a range of experimental conditions the tetrapeptide did not undergo conversion to Glp-Glu-Pro-NH,. This would indicate that the tripeptide and its extended forms are generated from a precursor that is related to semenogelin but in which Trp375 is replaced by glycine.Several studies have demonstrated the existence of TRHlike peptides (TRH, thyrotropin-releasing hormone) in the male reproductive system [l-51. The first to be identified was Glp-Glu-Pro-NH, (Glp, [3], which differs from TRH in the replacement of histidine by glutamic acid at position 2 of the tripeptide. In addition, other TRH-immunoreactive peptides have been reported which possess a neutral amino acid in place of the histidine of TRH [ 1, 51. Since their sequences do not occur in the TRH prohormone [6-81, it can be concluded that these TRH-like peptides originate from a different precursor and it was therefore considered of interest to identify their N-extended forms which are present in semen, with a view to devising probes that could be used for cloning their biosynthetic precursors. In addition, a knowledge of the sequence of the extended forms would allow their biological activities to be investigated. In this study we describe the isolation and identification of a series of Nextended forms of Glp-Glu-Pro-NH, from human semen. MATERIALS AND METHODS ReagentsSephadex G25, Sephadex G50 superfine, SP-Sephadex C25 and QAE Sephadex A25 were from Pharmacia Ltd. C8 Zorbax Octyl column was from Jones Chromatography Ltd and C18 pBondapak column was from Waters Ltd. Unless stated, all chemicals were of analytical grade and were from BDH Chemicals Ltd. Methanol and acetonitrile used in HPLC were Super Purity Solvent grade and were obtained from Romil Chemicals Ltd. Reagents and resin supports for peptide synthesis, including amino acid pentafluorophenyl esters, fluorenylmethoxycarbonyl (Fmoc) amino acids and trifluoroacetic acid were from LKB Biochrome Ltd. l-hydroxybenztriazole and dimethylformamide were from Applied...

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H. M. S. “Victory.”

Cited by 4 publications

References 0 publications

Specific processing of the thyrotropin-releasing prohormone in rat brain and spinal cord

Specific processing of the thyrotropin-releasing prohormone in rat brain and spinal cord

Enhancing the Learning of Fluid Mechanics Using Computer Simulations

Isolation and identification of N‐terminally extended forms of 5‐oxoprolylglutamylprolinamide (Glp‐Glu‐Pro‐NH₂), a thyrotropin‐releasing‐hormone(TRH)‐like peptide present in human semen

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H. M. S. “Victory.”

Cited by 4 publications

References 0 publications

Specific processing of the thyrotropin-releasing prohormone in rat brain and spinal cord

Specific processing of the thyrotropin-releasing prohormone in rat brain and spinal cord

Enhancing the Learning of Fluid Mechanics Using Computer Simulations

Isolation and identification of N‐terminally extended forms of 5‐oxoprolylglutamylprolinamide (Glp‐Glu‐Pro‐NH2), a thyrotropin‐releasing‐hormone(TRH)‐like peptide present in human semen

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Isolation and identification of N‐terminally extended forms of 5‐oxoprolylglutamylprolinamide (Glp‐Glu‐Pro‐NH₂), a thyrotropin‐releasing‐hormone(TRH)‐like peptide present in human semen