Figure 1.

Dependence of GCP activity in human skin biopsy on time of incubation - Human skin biopsies were sonicated for 2 min in ice. The resulting mixture was centrifuged at 16000 × g; precipitate from each preparation was used as GCP source in the activity assay. Incubations with [³H] NAAG (70 nM) at 37°C were carried out at 0.5, 1, 2, 3, 5, 7.5, 14, 18 and 24 h. Time points correspond to incubations carried out with biopsies obtained from different donors. Major plot illustrates the correspondence of enzyme activity ([³H]-glutamate production in dpm) with time while linearity was observed. Inset illustrates GCP activity measured at times up to 24 h.