Succinate dehydrogenase (EC 1.3.99.1) of Micrococcus luteus was selectively precipitated from Triton X-100-solubilized membranes by using specific antiserum. The precipitated enzyme contained equimolar amounts of four polypeptides with apparent molecular weights of 72,000, 30,000, 17,000, and 15,000. The 72,000 polypeptide possessed a covalently bound flavin prosthetic group and appeared to be ...

The distribution of (Na+ + K+) ATPase over the plasma membranes of distal convoluted tubules from canine kidney has been determined. This enzyme is responsible for the coupled active transport of Na+ and K+ across animal cell membranes. Ultrathin frozen sections were cut from fragments of renal cortex and specifically stained with antibodies, which recognize antigenic sites on the enzyme, and f...

Conventional equations for enzyme kinetics are based on mass-action laws, that may fail in low-dimensional and disordered media such as biological membranes. We present Monte Carlo simulations of an isolated Michaelis-Menten enzyme reaction on two-dimensional lattices with varying obstacle densities, as models of biological membranes. The model predicts that, as a result of anomalous diffusion ...

Background: Immobilization is an approach in industry to improve stability and reusability of urease. The efficiency of this technique depends on the type of membrane and the method of stabilization. Methods: The PEI-modified egg shell membrane was used to immobilize urease by absorption and glutaraldehyde cross-linking methods. The membranes were characterized by Fourier-transform infrared sp...

phospholipase a1 is known as an effective catalyst for hydrolysis of various phospholipids in enzymatic vegetable oil degumming. immobilization is one of the most efficient strategies to improve its activity, recovery and functional properties. in this study, chitosan-co-polyethylene oxide (90:10) nanofibrous mat was successfully fabricated and modified with atmospheric plasma at different time...

It has been shown that erythrocyte membrane proteins become susceptible to degradation by membrane-bound serine protease activity after oxidative modification of the membranes (M. Beppu, M. Inoue, T. Ishikawa, K. Kikugawa, Biochim. Biophys. Acta 1196 (1994) 81-87). The aim of the present study was to clarify the presence of the serine protease in oxidized erythrocyte membranes and to characteri...

The binding of ferredoxin-NADP reductase to spinach chloroplast membranes was studied by washing the membranes with different media. Release of the enzyme from the thylakoids was greater in 0.75 millimolar EDTA but was not complete inasmuch as 20% the activity remained membrane-bound after three washes.A Scatchard plot of binding experiments suggests the presence of one type of binding site and...

Acyltransferase activity is present in a variety of membranes species, including liver microsomes. The substrates of this enzyme are lysophosphatides and acyl CoA derivatives. We have found that the detergent effect of these substrates can be used to solubilize rat liver microsomes. If the solubilized fraction in incubated, the acyltransferase acylates the lysophosphatide and thereby degrades t...