. Author manuscript; available in PMC: 2015 Jul 10.

Published in final edited form as: Prostate. 2011 Mar 28;71(15):1680–1690. doi: 10.1002/pros.21385

TABLE I.

Comparison of Enzymatic Activity of Equal Amount of PSA in Different Conditions

Sample	Enzymatic activity (units^a)
Active f-PSA in assay buffer	30.44
Inactive f-PSA in assay buffer	0
Active f-PSA in HUVEC media	29.35
Inactive f-PSA in HUVEC media (with serum)^b	0
Inactive f-PSA in HUVEC media (without serum)^b	0
PSA in seminal plasma	35.95

Unit of enzymatic activity is defined as the amount of enzyme that cleaves 1 μM of substrate/min/ml.

Enzymatic activity was inhibited with 50 μM Zinc²⁺.