Abstract
Coupling of amino acids to 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) and 1,2,3,4-tetrahydro-7-hydroxyisoquinoline-3-carboxylic acid (HOTic) is difficult. In model experiments, use of 1-hydroxy-7-azabenzotriazole (HOAt) in combination with either N,N-diisopropylcarbodiimide (DIC) or O-(7-azabenzotriazol-1-yl)-1,1,3,3-Tetramethyluronium (HATU) for activation was effective in solving coupling difficulties. Based on this finding, HOTic was then incorporated into the 20-31 fragment of human epidermal growth factor (hEGF). [Abu20,31,HOTic22]hEGF(20-31)-NH2 was shown to be a 'difficult sequence', but replacement of the Tyr at position 29 with HOTic facilitates the complete dodecapeptide synthesis. Abbreviations: Tic, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid; HOTic, 1,2,3,4-tetrahydro-7-hydroxyisoquinoline-3-carboxylic acid; HBTU, 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate; BOP, benzotriazol-1-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate; PyBrop, bromo-tris(pyrrolidino)phosphonium hexafluorophosphate; DCC, N,N-dicyclohexylcarbodiimide; DIC, N,N-diisopropylcarbodiimide; HOBt, 1-hydroxybenzotriazole; HOAt, 1-hydroxy-7-azabenzotriazole; HATU, O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate; hEGF, human epidermal growth factor; Boc, t-butyloxycarbonyl; OtBu, t-butyloxy; Bzl, benzyl; OBzl, benzyloxy; 2ClZ, 2-chlorobenzyloxycarbonyl; Fmoc, fluorenylmethyloxycarbonyl; pMBHA, 4-methylbenzhydrylamine; NMP, N-methylpyrrollidinone; DCM, dichloromethane; DMF, N,N-dimethylformamide; DMSO, dimethyl sulfoxide; THF, tetrahydrofuran; DIEA, N,N-diisopropylethylamine; TFA, trifluoroacetic acid; TFMSA, trifluoromethanesulfonic acid; DMS, dimethyl sulfide; HPLC, high-performance liquid chromatography; ACN, acetonitrile.
| Original language | English |
|---|---|
| Pages (from-to) | 157-163 |
| Number of pages | 7 |
| Journal | Letters in Peptide Science |
| Volume | 7 |
| Issue number | 3 |
| DOIs | |
| State | Published - 2000 |
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All Science Journal Classification (ASJC) codes
- Biochemistry
Cite this
Difficulties in coupling to conformationally constrained aromatic amino acids. / Bozso, Z.; Toth, G.; Murphy, R. F.; Lovas, Sándor.
In: Letters in Peptide Science, Vol. 7, No. 3, 2000, p. 157-163.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Difficulties in coupling to conformationally constrained aromatic amino acids
AU - Bozso, Z.
AU - Toth, G.
AU - Murphy, R. F.
AU - Lovas, Sándor
PY - 2000
Y1 - 2000
N2 - Coupling of amino acids to 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) and 1,2,3,4-tetrahydro-7-hydroxyisoquinoline-3-carboxylic acid (HOTic) is difficult. In model experiments, use of 1-hydroxy-7-azabenzotriazole (HOAt) in combination with either N,N-diisopropylcarbodiimide (DIC) or O-(7-azabenzotriazol-1-yl)-1,1,3,3-Tetramethyluronium (HATU) for activation was effective in solving coupling difficulties. Based on this finding, HOTic was then incorporated into the 20-31 fragment of human epidermal growth factor (hEGF). [Abu20,31,HOTic22]hEGF(20-31)-NH2 was shown to be a 'difficult sequence', but replacement of the Tyr at position 29 with HOTic facilitates the complete dodecapeptide synthesis. Abbreviations: Tic, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid; HOTic, 1,2,3,4-tetrahydro-7-hydroxyisoquinoline-3-carboxylic acid; HBTU, 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate; BOP, benzotriazol-1-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate; PyBrop, bromo-tris(pyrrolidino)phosphonium hexafluorophosphate; DCC, N,N-dicyclohexylcarbodiimide; DIC, N,N-diisopropylcarbodiimide; HOBt, 1-hydroxybenzotriazole; HOAt, 1-hydroxy-7-azabenzotriazole; HATU, O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate; hEGF, human epidermal growth factor; Boc, t-butyloxycarbonyl; OtBu, t-butyloxy; Bzl, benzyl; OBzl, benzyloxy; 2ClZ, 2-chlorobenzyloxycarbonyl; Fmoc, fluorenylmethyloxycarbonyl; pMBHA, 4-methylbenzhydrylamine; NMP, N-methylpyrrollidinone; DCM, dichloromethane; DMF, N,N-dimethylformamide; DMSO, dimethyl sulfoxide; THF, tetrahydrofuran; DIEA, N,N-diisopropylethylamine; TFA, trifluoroacetic acid; TFMSA, trifluoromethanesulfonic acid; DMS, dimethyl sulfide; HPLC, high-performance liquid chromatography; ACN, acetonitrile.
AB - Coupling of amino acids to 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) and 1,2,3,4-tetrahydro-7-hydroxyisoquinoline-3-carboxylic acid (HOTic) is difficult. In model experiments, use of 1-hydroxy-7-azabenzotriazole (HOAt) in combination with either N,N-diisopropylcarbodiimide (DIC) or O-(7-azabenzotriazol-1-yl)-1,1,3,3-Tetramethyluronium (HATU) for activation was effective in solving coupling difficulties. Based on this finding, HOTic was then incorporated into the 20-31 fragment of human epidermal growth factor (hEGF). [Abu20,31,HOTic22]hEGF(20-31)-NH2 was shown to be a 'difficult sequence', but replacement of the Tyr at position 29 with HOTic facilitates the complete dodecapeptide synthesis. Abbreviations: Tic, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid; HOTic, 1,2,3,4-tetrahydro-7-hydroxyisoquinoline-3-carboxylic acid; HBTU, 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate; BOP, benzotriazol-1-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate; PyBrop, bromo-tris(pyrrolidino)phosphonium hexafluorophosphate; DCC, N,N-dicyclohexylcarbodiimide; DIC, N,N-diisopropylcarbodiimide; HOBt, 1-hydroxybenzotriazole; HOAt, 1-hydroxy-7-azabenzotriazole; HATU, O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate; hEGF, human epidermal growth factor; Boc, t-butyloxycarbonyl; OtBu, t-butyloxy; Bzl, benzyl; OBzl, benzyloxy; 2ClZ, 2-chlorobenzyloxycarbonyl; Fmoc, fluorenylmethyloxycarbonyl; pMBHA, 4-methylbenzhydrylamine; NMP, N-methylpyrrollidinone; DCM, dichloromethane; DMF, N,N-dimethylformamide; DMSO, dimethyl sulfoxide; THF, tetrahydrofuran; DIEA, N,N-diisopropylethylamine; TFA, trifluoroacetic acid; TFMSA, trifluoromethanesulfonic acid; DMS, dimethyl sulfide; HPLC, high-performance liquid chromatography; ACN, acetonitrile.
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U2 - 10.1023/A:1008928404072
DO - 10.1023/A:1008928404072
M3 - Article
VL - 7
SP - 157
EP - 163
JO - International Journal of Peptide Research and Therapeutics
JF - International Journal of Peptide Research and Therapeutics
SN - 1573-3149
IS - 3
ER -