title: [Activation of leucine aminopeptidase under hydrogen bond cleaving conditions].
abstract: Cleavage of hydrogen bonds by urea, guanidinium chloride or elevated temperatures causes a reversible activation of leucine aminopeptidase. The activation is similar to that caused by Mg2+ ions. This means that preincubation is required and that a 10-fold or more activated enzyme is inhibited by 50 mM cyanide to 20 per cent while a C1-ion-activated enzyme like the nonactivated enzyme is inhibited to 90 per cent. Blockage of the free SH-groups reduces the response time of the activation. The free SH-groups are involved in an essential intermediate step of the activation.
mesh_terms: D004789:Enzyme Activation; D006146:Guanidines / Q000494:pharmacology*; D006860:Hydrogen Bonding; D007700:Kinetics; D007931:Leucyl Aminopeptidase / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D011485:Protein Binding; D013696:Temperature; D013997:Time Factors; D014508:Urea / Q000494:pharmacology*
chemical_list: D006146:Guanidines; D014508:Urea; D007931:Leucyl Aminopeptidase; D008274:Magnesium
vernacular_title: Zur Aktivierung der Leuzinaminopeptidase unter Wasserstoffbrücken-lösenden Bedingungen