Kemps Acid Enzyme-Cleft and Self-Replication Models

2 Kemp s Acid Enzyme-Cleft and Self-Replication Models 

Biological catalysts — enzymes — are usually proteins. The development of new protein syntheses is nowadays dominated by genetic protein engineering (see section 4.1.16). Bio-organic approaches towards novel catalytically active structures and replicating systems try to manage without biopolymers. 

1 Enzyme-Cleft Models with Convergent Functional Croups 

(1987) first developed a new synthesis of Kemp s acid and then extensively explored its application in model studies. The synthesis involves the straightforward hydrogenation (A. Steitz, 1968), esterification and methylation of inexpensive 1,3,5-benzenetricar-boxylic acid (trimesic acid 30/100 g). The methylation of the trimethyl ester with dimethyl sulfate, mediated by lithium diisopropylamide(V. J. Shiner, 1981), produced mainly the desired all-cis-1,3,5-trimethyl isomer, which was saponified to give Kemp s acid. 

Heating Kemp s acid with appropriate aromatic diamines yields bis-imides with two convergently oriented carboxylic acid groups on the edges of a hydrophobic pocket. Dozens of interesting molecular complexes have been obtained from such compounds and can be traced in the Journal of the American Chemical Society under the authorship of J. Rebek, Jr., (1985 and later e.g. T. Tjivikua, 1990 B). 

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