Di-tert.-butyldicarbonat — ein vorteilhaftes Reagenz zur Einführung der tert.-Butyloxycarbonyl-Schutzgruppe

Moröder, Luis; Hallett, Allan; Wünsch, Erich; Keller, Oskar; Wersin, G.

doi:10.1515/bchm2.1976.357.2.1651

Cited by 312 publications

(59 citation statements)

References 4 publications

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“…Boc-Trp and Boc-Asp (where Bz = benzoyl) were prepared according to Morodes et al (9). Glu(-OBz) OBz-The publication costs of this article were defrayed in part by page charge payment.…”

Section: Methodsmentioning

confidence: 99%

On how a myosin tryptophan may be perturbed.

Bivin

Kubota²,

Pearlstein³

et al. 1993

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

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A weil-known indication that a nucleotide has bound to myosin Is the enhancement of the fluorescence of a speciflc tryptophan in the "subfragment 1" segment of the protein. Empirically the effect has been enormously useful in myosin enzymology. But beyond an early suggestion that it aries from a purine-tryptophan charge-transfer complex, the mechanism of the effect has not been considered. Here we consider the alternative that it arises from an Ionizable group (either another residue or the phosphate of the nucleotide) whose proimit to the tryptophan is altered by substrate bnding. We study this possibility by studying the interaction of an ionizable residue and tryptophan when both are incorporated in a diketopiperazine structure. The geometry of the ituation is inferred from molecular mehaics simulations. Unexpectedly, the best explanation seems to be that the field of the imposed charge, acting across space, affects events in the excited state of the indole.The perturbation of the absorbance (1) and emission (2) (8), but alternative explanations have not been considered. We undertook the present study, hoping to get clues about the aforementioned effect in myosin and, more generally, information about environmental effects on tryptophan. Our specific goal was to study the effect of a single charge positioned in a known relation to the indole ring, using a setup in which the sign and quantity of the charge (and to a limited extent the geometry of the arrangement) could be varied. We sought to accomplish this goal by using diketopiperazines constructed from. tryptophan and the L or D forms of amino acids such as histidine or aspartic acid, using appropriate molecular mechanical analysis to characterize the charge-indole relation. MATERIALS AND METHODSPreparation of the Diketopiperazines. The strategy followed was to prepare t-butoxycarbonyl (Boc)-protected amino acids, to couple these into linear dipeptide esters, and then to cyclize them and remove the protective groups.Boc-Trp and Boc-Asp(13-OBz) (where Bz = benzoyl) were prepared according to Morodes et al. (9). Glu(-OBz) OBz-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. 6791TosOH and His-OMe*2HCl were prepared according to Zervas et al. (10) and Humphlett and Wilson (11), respectively. Linear protected dipeptide esters were prepared by the N,N'-dicyclohexylcarbodiimide/N-hydroxysuccinimide method (12). Dimethylformamide was the solvent for coupling. The products were purified from ethyl acetate petroleum ether, except Boc-L-Trp-L-His-OMe, which was purified from warm ethanol. In TLC, each of the products gave a single spot (ninhydrin negative) using the KI/toluidine reaction for detection (13). To prepare the diketopiperazines, a Boc group was removed by dissolving 10 mmol of Bocprotected dipeptide ester in 120 ml (240 ml for the histidinecontaining dipeptide) of 0.1 M HCl/96% formic acid...

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“…Boc-Trp and Boc-Asp (where Bz = benzoyl) were prepared according to Morodes et al (9). Glu(-OBz) OBz-The publication costs of this article were defrayed in part by page charge payment.…”

Section: Methodsmentioning

confidence: 99%

On how a myosin tryptophan may be perturbed.

Bivin

Kubota²,

Pearlstein³

et al. 1993

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

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“…BOC derivatives of 3,4-dehydro-L-proline, ^-fluoro-D-phenylalanine, and ß-(3-quinolyl)-D-aalanine were obtained by using the procedure of Moroder et al [3,6]. The benzhydrylamine resin hydrochloride was obtained from Beckman Bioproducts, Palo Alto, California.…”

Section: Methodsmentioning

confidence: 99%

“…Coy et al [1] reported on the -"unexpectedly favorable outcome" -of introducing D-Lys 6 and D-Arg 6 Rivier et al [2] found that combinations of D-Trp and/or /?-(2-naphthyl)-D-a-alanine in positions 3 and/or 6 resulted in increases of antiovulatory potency in certain analogs.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Antiovulatory Activities in Rats of Analogs of the Luteinizing Hormone Releasing Hormone Having a Moiety of /?-(3-Quinolyl)-D-a-alanine in Positions 3 and 6

Folkers

Bowers

Kubiak

et al. 1983

Zeitschrift Für Naturforschung B

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Abstract Analogs of the luteinizing hormone releasing hormone (LHRH) having a moiety (D-Qal-) of β-(3-quinolyl)-D-α-alanine were synthesized toward more effective inhibitors of ovulation. [N-Ac-pCl-D-Phe1,2, D-3-Pal3, D-3-Qal6, D-Ala10]-LHRH was the most effective, and had an antiovulatory activity of 40% at 1 μg/rat. D-3-Qal6 was as effective as D-Trp6 in combination with N-Ac-3⊿Pro1, pF-D-Phe2, D-Trp3. D-Arg6 was superior to D-3-Qal6) in combination with N-Ac-pCl-D-Phe1,2, D-Trp3 (or D-3-Pal3), D-Ala10. The introduction of D-3-Qal3, D-His3 and D-Arg3 in comparable analogs caused substantial loss of activities.

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“…To produce 'head activator' amidated at the carboxy terminus, (< EPPGGSKVILF-NH,), the &-amino group of the lysine was first protected by tertiary butyloxycarbonate using a modified version of Moroder et al [17]. For amidation the protected 'head activator' (2 pmol) was dissolved in 0.5 ml of dichloromethane to which 22 p1 of N-methyl-morpholine (2 pmol) were added, and, after cooling to -15 "C, 20 p1 of isobutylchloroformiate (1.8 pmol) to form the mixed anhydride [18].…”

Section: Peptides and Peptide Fragmentsmentioning

confidence: 99%

Enzyme‐linked immunosorbent assay for the neuropeptide ‘head activator’

Schaller

Bodenmüller

Zachmann

et al. 1984

European Journal of Biochemistry

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By exposing different sites of the ‘head activator’, different sets of antibodies were designed and produced which recognised either the amino or the carboxy terminus of the free ‘head activator’, which reacted with ‘head activator’ in a tissue‐fixed conformation, or which bound to the ‘head‐activator’ sequence, if it was part of a larger precursor‐like molecule. An enzyme‐linked immunosorbent assay (ELISA) was developed to characterise the antibodies and also to assay minute amounts of ‘head activator’ or ‘head‐activator’‐like immunoreactivities in animal or tissue extracts. A competitive ELISA is described which uses biotin‐avidin for enhancement. The assay is sensitive with an antibody specific for the amino terminus in the range of 0.5–50 fmol, with an antibody specific for the carboxy terminus in the range of 20–400 fmol. The ELISA specific for the amino terminus is 10‐times more sensitive than a radio‐immunoassay with tritiated ‘head activator’ [H. Bodenmüller and B. Zachmann (1983) FEBS Lett. 159, 237–240]. Previously no radioimmunoassay existed with specificity for the carboxy terminus.

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Di-tert.-butyldicarbonat — ein vorteilhaftes Reagenz zur Einführung der tert.-Butyloxycarbonyl-Schutzgruppe

Cited by 312 publications

References 4 publications

On how a myosin tryptophan may be perturbed.

On how a myosin tryptophan may be perturbed.

Synthesis and Antiovulatory Activities in Rats of Analogs of the Luteinizing Hormone Releasing Hormone Having a Moiety of /?-(3-Quinolyl)-D-a-alanine in Positions 3 and 6

Enzyme‐linked immunosorbent assay for the neuropeptide ‘head activator’

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