Improved method for hydrolyzing proteins and peptides without inducing racemization and for determining their true D-amino acid content.
A new method of hydrolyzing proteins and peptides without racemizing the amino acids has been developed. This method consists of performing a brief partial chemical hydrolysis for 15 min in 6 M HCl at 80-90 degrees C, followed by an enzymatic hydrolysis with pronase for 12-16 h at 50 degrees C, and finally an enzymatic hydrolysis with leucine aminopeptidase and peptidyl-D-amino acid hydrolase for 24 h. Using this new method the time required for complete hydrolysis of proteins is less than 3 days. The total hydrolysis averages 97-100%, and the amount of racemization of the amino acids is less than 0.002%. This method may then be used as a tool to easily determine the intrinsic D-amino acid content of peptides or proteins from animal or vegetable tissues.
D'Aniello
A
A
Department of Biochemistry and Molecular Biology, Zoological Station A Dohrn, Naples, Italy.
Petrucelli
L
L
Gardner
C
C
Fisher
G
G
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis*; D000818:Animals; D007887:Fabaceae; D006868:Hydrolysis; D008099:Liver / Q000737:chemistry; D008969:Molecular Sequence Data; D049831:Octopodiformes; D010455:Peptides / Q000032:analysis*; D010940:Plant Proteins / Q000032:analysis; D010946:Plants, Medicinal; D011506:Proteins / Q000032:analysis*; D013237:Stereoisomerism
D000596:Amino Acids; D010455:Peptides; D010940:Plant Proteins; D011506:Proteins