The specific activities of highly purified preparations of human parotid and pancreatic amylase on several different soluble and insoluble starches were compared. The ratio of parotid to pancreatic activity varied with the physical nature of the substrate. With all soluble starches, irrespective of source, parotid amylase exhibited a higher specific activity than did pancreatic amylase; the rev...

In this work, we hypothesize that a surface modified with both polyethylene glycol (PEG) and hirudin may provide a non-fouling, thrombin-neutralizing surface suitable for blood contacting applications. With gold as a model substrate we used two different approaches to the preparation of such a surface: (1) a "direct" method in which PEG was conjugated to hirudin and the conjugate was then immob...

Lipases are versatile enzymes with high specificity toward lipid substrate. They have many industrial applications, such as in food, pharmacy, and green fuel. So far, most explored lipases from microbial animal sources, whereas those plants less studied. The present study aims to characterize ketapang (Terminalia catappa Linn) lipase. lipase was isolated germinating seeds. activity determined b...

Implantation S1 family serine proteinases (ISPs) are tryptases involved in embryo hatching and uterine implantation in the mouse. The two different ISP proteins (ISP1 and ISP2) have been detected in both pre- and post-implantation embryo tissue. To date, native ISP obtained from uterus and blastocyst tissues has been isolated only as an active hetero-dimer that exhibits trypsin-like substrate s...

The effect of pH on the steady state kinetics of gamma-glutamyl transferase (GGT) from Bacillus subtilis was examined using glutamyl-(3-carboxyl)-4-nitroanilide as the chromogenic reporter substrate. The enzyme was active in the pH range 7.0-11.0 with the optimum activity at pH 11.0. We noticed a pH dependent transformation in the nature of substrate consumption kinetics. The substrate saturati...

The amidolytic activity of activated kallikrein in plasma can be measured by use of the chromogenic substrate, S-2302 (H-D-Pro-Phe-Arg-pNA). Plasma prekallikrein was activated to kallikrein by exposure to 50 mg/L dextran sulfate in acetone/water (35/65 by vol) at 0 degrees C for 15 min. The acetone slows anti-kallikrein activity and increases the kallikrein activity by 30%. The 37 degrees C rea...

In haemodialysis low-molecular-weight (LMW) heparin is increasingly used for anticoagulation. The advantages over unfractionated (UF) heparin are the lower bleeding risk and the lack of influence on lipid metabolism. However, no reliable and rapid method is available so far to control the efficacy and safety of LMW heparin during haemodialysis. The specific anti-factor Xa (aXa) chromogenic subs...

Polydiacetylenes (PDAs) form a unique class of polymeric materials that couple highly aligned and conjugated backbones with tailorable pendant sidegroups and terminal functionalities. They can be structured in the form of bulk materials, multilayer and monolayer films, polymerized vesicles, and even incorporated into inorganic host matrices to form nanocomposites. The resulting materials exhibi...