The recognition that the hydrolysis of the peptides, glycylglycine and glycyl-n-leucine, is due to specific dipeptidases (l-3) has led to a search for an explanation of why the responsible enzymes should require such extremely specific substrate configurations. While a complete description is obviously not yet possible, a partial answer seems to be in the role that certain metals play in these ...

Experimental conditions were as follows: MgS04 , 10 pmoles; L-ornithine, 5 rmoles; glycylglycine, pH 7.5, 50 pmoles; NHIHC03, 5 Fmoles; ATP, 5 pmoles; phosphoenolpyruvate, 5 pmoles; ornithine transcarbamylase (beef liver) 17 units; phosphoenolpyruvate kinase, 513 Biicher units; frog liver carbamyl phosphate synthetase, 0.1 ml (0.825 mg); final volume, 1.00 ml; incubation for 15 minutes at 37”. ...

Many hydrogenotrophic methanogens use either H2 or formate as the major electron donor to reduce CO2 for methane production. The conventional cultivation of these organisms uses H2 and CO2 as the substrate with frequent replenishment of gas during growth. H2 is explosive and requires an expensive gassing system to handle safely. Formate is as an ideal alternative substrate from the standpoints ...

A series of SPM VIII analogs were synthesized to investigate the effect of the amino acid moiety on the antitumor activity. The L-threonine analog and the glycylglycine analog of SPM VIII showed much higher cytotoxicity to P388 murine leukemia cells (IC50 5.8 nM and 0.11 nM, respectively) than SPM VIII (IC50 25nM). However, replacement of the glycine moiety with other amino acids greatly reduce...

In an earlier report (1) it was shown that a band characteristic of the peptide bond appeared in the ultraviolet and that values of the molar absorption coefficient (em) at 205 mp could be used to characterize this band. It was shown, for a series of proteins, that the contribution of each peptide bond (ep) to the molar absorption coefficient is fairly constant, lying between 2500 and 2800. The...

In an earlier report (1) it was shown that a band characteristic of the peptide bond appeared in the ultraviolet and that values of the molar absorption coefficient (em) at 205 mp could be used to characterize this band. It was shown, for a series of proteins, that the contribution of each peptide bond (ep) to the molar absorption coefficient is fairly constant, lying between 2500 and 2800. The...

Ternary complexes of copper(II) and zinc(II) metal ions with the ligands maltol; 3-hydroxy-2-methyl-4H-pyrone (MA) and glycylglycine (GG) have been synthesized and characterized by IR, H NMR, UV-Visible, mass spectra and TGA techniques. The complexes have been screened for antibacterial activity and the results are compared with the activity of free ligands. Increased activity of ternary comple...