Proteolytic enzymes in peptide synthesis

Konopińska, Danuta; Muzalewski, Feliks

doi:10.1007/bf00230403

Cited by 17 publications

(3 citation statements)

References 33 publications

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“…The largest contribution to the free energy change during hydrolysis of a peptide bond comes from the ionization of the liberated amino and carboxyl groups. Thus, if these groups on two substrate amino acids are 'blocked', then the reverse reaction, peptide-bond synthesis, may be catalysed by the enzyme under mild conditions (Fruton, 1982;Konopinska & Muzalewski, 1983;Jakubke et al 1985). The major advantages of the enzyme method are stereospecificity of the reaction, lack of racemization and better economy in large-scale production (Fruton, 1982).…”

Section: Production O F Synthetic Dipeptides or Protein Hydrolysates mentioning

confidence: 99%

Peptides in Human Nutrition

Grimble

Silk

1989

Nutr. Res. Rev.

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Section: Production O F Synthetic Dipeptides or Protein Hydrolysates mentioning

confidence: 99%

Peptides in Human Nutrition

Grimble

Silk

1989

Nutr. Res. Rev.

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“…It has been known since the beginning of the 20th century that the protease-catalyzed hydrolysis of peptide bonds is generally reversible. However, it took Ͼ50 y until the potentials of this method were recognized and further developed (Konopinska andMuzalewski 1983, Jakubke et al 1985). The obvious advantages of an enzymecatalyzed peptide synthesis are the (stereo)-specificity of the reaction, the possibility to minimize protection of functional groups and the feasibility to use free amino acids as nucleophiles.…”

Section: Dipeptide Conceptmentioning

confidence: 99%

New Developments in Glutamine Delivery

Fürst

2001

The Journal of Nutrition

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Numerous studies demonstrate that free glutamine can be added to commercially available crystalline amino acid-based preparations before their administration. Instability during heat sterilization and prolonged storage and limited solubility (35 g/L at 20°C) hamper the use of free glutamine in the routine clinical setting. Indeed, there are many well-controlled and valuable trials with free glutamine, yet its use is restricted to clinical research. The obvious limitations of using free glutamine initiated an intensive search for alternative substrates. Synthetic glutamine dipeptides are stable under heat sterilization and highly soluble; these properties qualify the dipeptides as suitable constituents of nutritional preparations. Industrial production of these dipeptides at a reasonable price is an essential prerequisite for implications of dipeptide-containing solutions in clinical practice. Recent development of novel synthesis procedures allows increased capacity in industrial-scale production. Basic studies with synthetic glutamine-containing short-chain peptides provide convincing evidence that these new substrates are cleared rapidly from plasma after parenteral administration, without being accumulated in tissues and with negligible loss in urine. The presence of membrane-bound as well as tissue-free extracellular hydrolase activity facilitates a prompt and quantitative peptide hydrolysis, the liberated amino acids being available for protein synthesis and/or generation of energy. In the clinical setting, glutamine dipeptide nutrition beneficially influences outcome (nitrogen balance, immunity, gut integrity, hospital stay, morbidity and mortality). The provision of conditionally indispensable glutamine should be considered a necessary replacement of a deficiency rather than a supplementation. The beneficial effects observed with glutamine dipeptide nutrition should be seen simply as a correction of disadvantages produced by the inadequacy of conventional clinical nutrition. The availability of stable dipeptide preparations certainly facilitates, for the first time, adequate amino acid nutrition of critically ill, malnourished or stressed patients in the routine clinical setting and, thus, represents a new dimension in artificial nutrition.

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“…It has been known since the begin ning of the 20th century that the protease-cat alyzed hydrolysis of peptide bonds is general ly reversable. However, it took more than 50 years until the potentials of this method were recognized and further developed [34,35], The obvious advantages of an enzyme-cata lyzed peptide synthesis are the (stereo-)specifity of the reaction, the possibility to minimize protection of functional groups and the feasi bility to use free amino acids as nucleophiles.…”

Section: Syn Th E Sis and Characterization Of Parenteral Dipeptidesmentioning

confidence: 99%