Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0220723 (
PCA
)
4,687
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
[3H]Glutamic acid (
PCA
) was followed with time after a single subcutaneous injection.
PCA
specific activity increased slowly, reaching a peak at 3 to 4 days after injection of the labeled amino acid, after which it slowly decline. Incorporation of [3H]glutamic acid into epidermal
PCA
was markedly inhibited by a single topical application of cycloheximide. Topical application of cycloheximide 2 hr prior to [3H]glutamate injection caused a significantly greater reduction in
PCA
specific activity (determined 3 days after injection) than cycloheximide treatment 3 hr after administration of the labeled amino acid. Ninety-seven percent of the
PCA
content of
hairless
mouse epidermis was shown to reside in the stratum corneum. These observations indicate the involvement of protein synthesis in the formation of
PCA
from glutamic acid rather than a direct conversion of the amino acid. The high level of
PCA
in mammalian epidermis appears to be caused by its accumulation in the stratum corneum accompainied by a relatively slow rate of
PCA
turnover in comparison to other tissues.
...
PMID:Biosynthesis of pyrrolidone carboxylic acid in hairless mouse epidermis. 87 May 63
Recent literature has suggested that pyroglutamate (
PCA
) formation in stratum corneum occurs by spontaneous cyclization of glutamine residues derived from filaggrin breakdown. This paper describes an enzymatic alternative. Epidermal homogenates from
hairless
mice were found to catalyze the formation of
PCA
from both glutamine and glutamic acid at pH 6.2. Enzyme activity responsible for the first step in this reaction, gamma-glutamyl peptide formation, was partially purified using ammonium sulfate precipitation followed by ion exchange, gel filtration, and hydroxylapatite chromatography. Enzyme preparations free of gamma-glutamyl cyclotransferase activity (which forms
PCA
from certain gamma-glutamyl peptides) catalyzed formation of gamma-glutamyl-glutamine from glutamine and gamma-glutamyl-glutamate from glutamic acid. Enzyme preparations catalyzed hydrolysis of a variety of gamma-glutamyl peptides but did not split non-gamma-glutamyl peptides or the transpeptidase substrate gamma-glutamyl-rho-nitroanilide. Ammonium sulfate fractions containing both gamma-glutamyl peptidase and gamma-glutamyl cyclotransferase activity catalyzed linear formation of
PCA
from glutamic acid for periods of up to 19 h. Using gamma-glutamyl-leucine as a substrate, gamma-glutamyl peptidase activity was found to be much higher in crude extracts from epidermis than in preparations from liver, kidney, spleen, intestine, lung, brain, or heart. This activity has not, to our knowledge, been previously described in mammalian tissues.
...
PMID:Gamma glutamyl peptidase: a novel enzyme from hairless mouse epidermis. 289 53
