Peptidylglycine α-amidating monooxygenase (PAM), with enzymatic domains that utilize Cu and Zn, is the only enzyme that catalyzes this reaction.PAM activity is detected in serum, but its significance and utility as a clinical biomarker remain unexplored.Mice heterozygous for the mutant PAM allele develop normally and express wildtype levels of several amidated peptides despite having one half the wildtype levels of PAM activity and PAM protein.
To assess this effect on batch and perfusion cultures, the culture temperature was shifted from 37 to 32 °C in the mid-exponential phase in the case of batch culture and from 37 to 34 °C when the cell density became high enough in the case of perfusion culture.
The method presented here would contribute to production of bioactive proteins using other recombinant cell lines.
Peptidylglycine alpha-amidating monooxygenase (PAM) catalyzes the COOH-terminal amidation of peptide hormones.
Different amidation events on chromogranin A, and on peptides processed from proopiomelanocortin, manifest similar striking sensitivity to hypoxia in a range of neuroendocrine cells, being progressively inhibited from mild (7% O2) to severe (1% O2) hypoxia.
In developing Drosophila melanogaster larvae, FMRF amidation in thoracic ventral (Tv) neurons is strikingly suppressed by hypoxia.