title: Kinetics of peptide hydrolysis and amino acid decomposition at high temperature.
abstract: Dipeptide hydrolysis and amino acid decomposition appear to follow a first-order rate law.  The hydrolysis rate increases exponentially with increasing temperature in aqueous solution at both 265 atm and water steam pressures over the temperature range of 100 to 220 degrees C.  Dipeptide hydrolysis has a lower apparent activation energy at 265 atm (44.1 KJ/mol) than at water steam pressure (98.9 KJ/mol).  At lower temperatures (<200-220 degrees C), the rate of peptide bond hydrolysis is faster at 265 atm than at water steam pressure.  At higher temperatures (>200-220 degrees C), however, peptide bond hydrolysis is slower at 265 atm than at water steam pressure.  In aqueous solution, amino acid decomposition rates also increase exponentially with increasing temperature.  Amino acid decomposition rates are much higher at 265 atm than at water steam pressure over the entire temperature range investigated.
authors.affiliation: School of Geology and Geophysics, The University of Oklahoma, Norman 73019, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Qian
authors.forename: M H
authors.initials: MH
authors.lastname: Engel
authors.forename: S A
authors.initials: SA
authors.lastname: Macko
authors.forename: S
authors.initials: S
authors.lastname: Carpenter
authors.forename: J W
authors.initials: JW
authors.lastname: Deming
mesh_terms: D000409:Alanine / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry*; D001274:Atmospheric Pressure; D018698:Glutamic Acid / Q000737:chemistry; D005998:Glycine / Q000737:chemistry; D006033:Glycylglycine / Q000737:chemistry*; D006358:Hot Temperature; D006868:Hydrolysis; D007700:Kinetics; D009792:Oceans and Seas; D010455:Peptides / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000596:Amino Acids; D010455:Peptides; D006033:Glycylglycine; D018698:Glutamic Acid; D000409:Alanine; D005998:Glycine