Several esters of 4-methylumbelliferone and 2-naphthol were synthesized and examined as possible spectrofluorimetric titrants for bovine alpha-chymotrypsin, trypsin, thrombin, Factor Xa and for subtilisin Novo. 4-Methylumbelliferyl p-guanidinobenzoate hydrochloride (MUGB) is a satisfactory titrant for alpha- and beta-trypsin, thrombin and Factor Xa and 4-methylumbelliferyl p-(NNN-trimethylammonium)cinnamate (MUTMAC) is a good titrant for alpha-chymotrypsin. The amount of enzyme used for spectrofluorimetric titration is 0.02-3.00nmol and the amount of 4-methylumbelliferone liberated is independent of the concentration of titrant and stoicheiometrically equal to the amount of enzyme used. Results obtained with MUGB and MUTMAC have been checked by spectrophotometric titration with p'-nitrophenyl p-guanidinobenzoate hydrochloride and p-nitrophenyl N(2)-acetyl-N(1)-benzylcarbazate respectively. p-Nitrophenyl N(2)-acetyl-N(1)-(9-anthrylmethyl)carbazate has been synthesized; it did not react with alpha-chymotrypsin. A satisfactory spectrofluorimetric titrant for subtilisin Novo was not discovered.

This text is suitable for advanced undergraduate and beginning graduate students in chemistry and biochemistry studying amino acids and peptides. The authors concentrate on amino acids and peptides without detailed discussions of proteins, although the book gives all the essential background chemistry, including sequence determination, synthesis and spectroscopic methods, to enable the reader to appreciate protein behaviour at the molecular level. The approach is intended to encourage the reader to cross classical boundaries, as in the later chapters on the biological roles of amino acids and the design of peptide-based drugs. For example, there is a section on the enzyme-catalysed synthesis of peptides, with suitable examples, an area often neglected in texts describing peptide synthesis. This modern text will be of value in the amino acid, peptide and protein field, to advanced undergraduates, graduate students and research workers.

1-(N-Amino-n-hexyl)carbamoylimidazole hydrochloride was synthesized and shown to be a potent irreversible inhibitor of human urokinase (EC 3.4.21.31), pig kidney-cell plasminogen activator (EC 3.4.21.-), human plasmin (EC 3.4.21.7) and bovine pancreatic beta-trypsin (EC 3.4.21.4). The kinetics of inhibition of the enzymes were determined by monitoring the hydrolysis of an appropriate fluorogenic substrate. Bovine thrombin and Factor Xa are hardly affected by the inhibitor.

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Thionoleucine S-anilide (Leut-anilide), Leut-Gly-OEt and Leut-Phe-OMe were synthesized and shown to be competitive inhibitors of leucine aminopeptidase from pig kidney. The kinetics of inhibition were determined in the presence of leucine 4-methylcoumarin-7-amide as substrate. Although the compounds showed only moderate inhibitory potency, it was found that all were resistant to hydrolysis by the enzyme, in contrast with the reported behaviour of some thionopeptide analogues of substrates for other Zn2+-peptidases such as carboxypeptidase A and angiotensin-converting enzyme.