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Biomedical subjects

A Könnecke

Publications and source records attributed to A Könnecke.

5 recordsLinked to original sources
PubMed1990

Biospecific adsorbents on the basis of chloroformate-activated bead cellulose.

Carbohydrate-derived polymers are activated by the chloroformate N-chlorocarbonyloxy-5-norbornene-2.3-dicarboximide (ClCOONB). The advantages of this activation method are presented. The application of bead cellulose as adsorbent for biomedical and biotechnological purposes is demonstrated. Examples for immunoglobulin purification, streptavidin isolation, and biotransformation of porcine insulin are given.

Bacterial Proteins↗
PubMed1982

Investigations on the substrate specificity of thermitase, a thermostable serine-protease from Thermoactinomyces vulgaris.

The kinetic parameters Km and kcat and the proteolytic coefficients kcat/Km for the hydrolysis of eighteen Z(benzyloxycarbonyl)-dipeptide methyl esters with variation of the residues in P1 and P2 position catalyzed by thermitase at pH 8 and 55 degrees C are reported. The results indicate that an integral part of both subsites, S1 and S2, are hydrophobic areas and that a mutual interaction between the side chains of P1 and P2 for optimal hydrolyisis does exist. Furthermore, the importance of the P2 for the peptidolytic activity of thermitase was shown using N-acylated oligo-alanine peptides and their p-nitroanilides. In all cases dialanine or alanine p-nitroanilide are the main products.

Endopeptidases↗
PubMedDate not supplied

Protease-catalyzed peptide synthesis: prevention of side reactions in kinetically controlled reactions.

One major problem in protease-catalyzed peptide synthesis is the occurrence of unwanted proteolytic side reactions. The objective of this study was to demonstrate that specific acyl donor esters can efficiently prevent the enzymatic hydrolysis of the peptide product. As a model system, we have studied the alpha-chymotrypsin-catalyzed synthesis of peptides which are specific chromogenic substrates for this enzyme. The leaving group of the carboxyl component was shown to be of major influence on this process. The accumulating protease-labile peptide product can be protected against enzyme action by a sufficient concentration of a specific acyl donor ester. The parameter alpha 1 that gives the ratio of second-order rate constants for the enzymatic hydrolysis of the peptide product and the acyl donor plays a key role in the synthesis of protease-labile peptides. We could establish that highly protease-labile peptides can be enzymatically synthesized in a homogeneous phase.

Acylation↗