l-Homoarginine

摘要: Abstract It is known that l-homoarginine fails to inhibit human intestinal and placental alkaline phosphohydrolases under conditions which produce inhibition of bone liver isoenzymes. Now, the mechanism by phosphatases has been investigated. Results were very similar for these two isoenzymes resembled other organ-specific inhibitors phosphatase isoenzymes; l-phenylalanine l-tryptophan which, however, but not Thus, was independent pH, dependent on substrate concentration up 5 mm. Further increase concentration, had little effect inhibition. The double reciprocal plots 1/v versus 1/s at various concentrations showed a series parallel lines indicating "uncompetitive." Partial denaturation enzyme with heat, urea, or papain digestion no shift optimum temperature maximum velocity higher temperature, from 37–45° isoenzyme 39–45° isoenzyme, observed when inhibitor present in digest. Hyperbolic curves obtained percentage plotted against different temperatures. n value apparent number molecules combining one active site molecule calculated be 1.02 1.04 0.90 0.94 phosphatases.