Original scientific paper

Synthesis of the Four Structural Isomeric L-Pentapeptides of Ala. Glu. Lys. Ala. Ala. Sequence: Characterization and Correlation with the L-D-L-D-D-lsomer Related to the Peptidoglycan Peptide Chain

D. Goleš ; Tracer Laboratory, Department -of Organic Chemistry and Biochemistry, Institute »Ruder Boskovic«, 41001 Zagreb, Croatia, Yugoslavia
L. Tomić ; Tracer Laboratory, Department -of Organic Chemistry and Biochemistry, Institute »Ruder Boskovic«, 41001 Zagreb, Croatia, Yugoslavia
D. Keglević ; Tracer Laboratory, Department -of Organic Chemistry and Biochemistry, Institute »Ruder Boskovic«, 41001 Zagreb, Croatia, Yugoslavia

Abstract

The synthesis of the four L-pentapeptides containing the Ala.
Glu. Lys. Ala. Ala. sequence, which differ with regard to the 'sHe
of linkage between the glutamyl-lysyl residues, is described.
In each case the chain was built by coupHng the protected N-
termi:nal dipeptide N-hydroxysuccinimide esiter (II or IV) with
the C-terminal tripeptide benzyl ester (VIII or X). The sequentially
.identical L-D-L-D-D-pentapeptide having the y-carboxy-group
of D-glutamic acid residue involved in the .peptide ·bond, was prepared
after the same general pattern. Complete deprotection of the
isomers i111 two successive steps gave the free pentapeptides which
were characterized as solid di-trifluoroacetate salts by analytical,
optical and proton NMR spectral data. The isomers were compared
by paper electrophoresis at different pH values. The alantne methyl
resonances in the NMR spectra of the a-a L-pentapeptide XVIII
and the y-a L-D-L-D-D-pentapeptide XXII were assigned by observing
the shift in spectral lines with varying pH.

Keywords

Hrčak ID:

196468

URI

https://hrcak.srce.hr/196468

Publication date:

23.9.1976.

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