The influence of peptidyl-prolyl cis-trans isomerase on the in vitro folding of type III collagen.
Peptidyl-prolyl cis-trans isomerase was extracted from pig kidney cortex and partially purified. Enzyme activity was monitored against the cis-trans isomerization of succinyl-Ala-Ala-Pro-Phe-methylcoumaryl amide by means of a two-step process using chymotrypsin as the trans cleaving activity. The in vitro refolding of denatured type III collagen, which is rate-limited by the cis-trans isomerization of peptide bonds, was studied in the presence of peptidyl-prolyl cis-trans isomerase by optical rotatory dispersion and by resistance to tryptic digestion. A 3-fold increase in the initial rate of folding was observed compared to the uncatalyzed refolding. This rate increase is comparable to the rate increase found for the CT-phase in the refolding of urea-denatured ribonuclease A, but it is smaller than the increase in the rate of isomerization of succinyl-Ala-Ala-Pro-Phe-methylcoumarylamide.
Bächinger
H P
HP
Research Unit, Shriners Hospital for Crippled Children, Portland, Oregon 97201.
D000591:Amino Acid Isomerases / Q000378:metabolism*; D003094:Collagen; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D019696:Peptidylprolyl Isomerase; D011487:Protein Conformation; D011489:Protein Denaturation
D003094:Collagen; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase