A Versatile Microassay for Elastase Using Succinylated Elastin

Multiple matrix metalloproteinases in type II collagen induced arthritis

“…MMP-2 was assayed using 50mM borate buffer pH 7 containing 10 mM CaCl 2 and MMP-9 using 50mM borate buffer pH 8.5, 0.03% TNBSA was added and OD measured at 450nm (26).…”

Sensitivity and lower protease activity of Candida albicans species isolated from Egyptian cancer patients after exposure to cytotoxic and/or radiotherapy treatment

“…Protease activity of C. albicans was assessed by a commercial kit (Pierce Quantitative Protease Assay Kit, Thermoscientific, 23263, Hyclone, USA) according to the method described in Rao et al (1997) and modified by Tian et al (2004). The inoculums were adjusted to 0.8 at 550 nm to get 10⁸ cells/ml as described by the manufacturer's protocol.…”

Automated Determination of Serum α1-Antitrypsin by Antitryptic Activity Measurement

“…We diluted 2,4,6 trinitrobenzene sulfonic acid (TNBSA) 5% (Sigma P2297) before use in borate buffer 0.04 mol/L (sodium tetraborate ϩ hydrochloric acid sufficient for pH 8.5) to a final concentration of 3 ϫ 10 -4 mol/L; 0.5 g/L porcine trypsin, minimum 250 USP units/mg in 0.2% EDTA (Eurobio), was diluted to 0.025 g/L in borate buffer (pH 8.5) and stored at Ϫ20°C. Gelatin 2% solution (Sigma G 1393) was succinylated using a standard procedure described by Rao and coworkers (11 ). Briefly, 20 mL of gelatin 2% was diluted with 10 mL borate buffer, followed by addition of 500 mg of succinic anhydride in very small increments to the solution while it was stirred with a magnetic stirrer.…”

“…Assays for the activity of proteolytic enzymes were developed in the 1960s; the inhibition of proteolytic enzyme activity was then used to measure the antiprotease activity of serpins, particularly the most abundant of these, A1AT and ␣2-macroglobulin (9 ). The principle of the reaction has not changed since its development, and the only modifications have been in the choice of the substrate: synthetic (10 ), chromo-or fluorogenic (such as n-␣-benzoyl-DL-arginine-pnitroanilid), or natural (such as elastin or gelatin) (11 ). These techniques have been partially automated, but a manual predilution of the samples is still required (12,13 ); these methods have also been adapted to 96-well microplates for a limited series of studies (14 ).…”