In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against g...

Recently palladium catalysts have been discovered that enable the directing-group-free C−H activation of arenes without requiring an excess arene substrate, thereby enabling methods for late-stage modification complex organic molecules. The key to success has use two complementary ligands, N-acyl amino acid and N-heterocycle. Detailed experimental computational mechanistic studies on dual-ligan...

Although the syntheses of novel and diverse peptides rely mainly on traditional coupling using unnatural amino acids, postsynthetic modification of peptides could provide a complementary method for the preparation of nonproteinogenic peptides. Site selectivity of postsynthetic modification of peptides is usually achieved by targeting reactive moieties, such as the thiol group of cysteine or the...

Chemical modification of aminopeptidase from pronase has revealed two important histidines in enzyme catalysis. In the absence of metal ions, modification of the readily-modified histidine (pKa 6.9 +/- 0.5) results in a drastic loss of activity, indicating that this residue is indispensible for enzyme activity. In the presence of CaCl2, the modified enzyme still retains approx. 60% of the activ...

The affinity label 5'-p-(fluorosulfonyl)benzoyl adenosine modifies rabbit muscle phosphofructokinase to the extent of one group/subunit. Modification appears to occur at a binding site specific for AMP, cyclic AMP, and ADP, i.e. those adenine nucleotides which are activators under conditions where regulatory kinetic behavior is obtained. The consequences of the modification are consistent with ...

In this paper we study the ultrasensitive behavior of multisite phosphorylation or ligand binding systems, under site-to-site variations in the modification rates. Using computational methods and mathematical analysis, we prove that the Hill coefficient reaches its maximum value when all sites are identical to each other. This is shown for a non-cooperative multisite system with arbitrary activ...

Diese Dissertation wurde selbständig, ohne unerlaubte Hilfe erarbeitet.

Enzyme inactivation was utilized to study subunit interaction in the homotetrameric glycolytic enzyme, aldolase. Isoenzymes from rabbit liver and skeletal muscle were inactivated in the presence of Pi and d-glyceraldehyde-P to a maximum stoichiometry of one modification per aldolase subunit. Subunit modification increased net negative charge on each subunit surface and was used to resolve modif...