Membrane particle

Yoshida S, Uemura M, Niki T, Sakai A, Gusta LV. Partition of membrane particles in aqueous two-polymer system and its partial use for purification of plasma membranes from plants. Plant Physiol 1983 72 105-114. 

The terminal complex hypothesis proposes that the cellulose synthesizing enzyme complex can be visualized with electron microscopy. Terminal complex is the name given to collections of plasma membrane particles thought to represent the cellulose synthase. While direct evidence is still not available to support this hypothesis, the amount of indirect supporting evidence has grown dramatically in the past few years. The relationship between terminal complexes, cellulose physical structure and the biochemical events of cellulose biosynthesis will be discussed. 

A6. Aupeix, K., Hugel, B., Martin, T, Bischoff, R, Till, H., Pasquali, J. L., and Freyssinet, J. M., The significance of shed membrane particles during programmed cell death in vitro and in vivo in HIV-1 infection. J. Clin. Invest. 99, 1546-1554 (1997). 

Azarnia R, Dahl G, Loewenstein WR Cell junction and cyclic AMP. III. Promotion of junctional membrane permeability and junctional membrane particles in a junction-deficient cell type. J Membr... 

Fig. 2 a. Elcctronmicrograph of a freeze fractured preparation of isolated sarcoplasmic reticulum vesicles. 9 nm membrane particles are clearly visible on the concave cytoplasmic fracture faces of the vesicular membranes... 

ATP synthase complexes These complexes of proteins are referred to as inner membrane particles and are attached to the inner surface of the inner mitochondrial membrane. They appear as spheres that protrude into the mitochondrial matrix. 

Through the use of freeze-fracture and freezeetching techniques of electron microscopy, it is possible to see, embeddded in the thylakoid membranes, particles which may represent individual photosyn-thetic units (also called quantosomes).227 256-258 They are about 20 nm in diameter, and at least many of them presumably contain a reaction center surrounded by light-collecting chlorophyll-protein complexes. Others may represent the cytochrome b6f complex and... 

Particles smaller than the largest pores, but larger than the smallest pores are partially rejected, according to the pore size distribution of the membrane. Particles much smaller than the smallest pores will pass through the membrane. Thus, separation of solutes by microporous membranes is mainly a function of molecular size and pore size distribution. In general, only molecules that differ considerably in size can be separated effectively by microporous membranes, for example, in ultrafiltration and microfiltration. 

Newman, PJ. and Sherman, L.A. 1978. Isolation and characterization of the photosystem I and II membrane particles from the blue-green alga Synechococcus cedrorum. Biochim. Biophys. Acta, 503. 343-361. 

When using the encapsulation method the enzyme is enclosed in a scmipcrmeablc membrane. Particles of 1 -... 

W.R. Bowen and A.O. Sharif, Transport through microfiltration membranes—particle hydrodynamics and flux reduction. J. Colloid interface Sci. 168 (1994) 414-421. 

First, assume that the surface charge on the membrane particles does not interact with the mobile protons (no proton release or uptake). An ion step will result in an increase in the double-layer capacitances of the particles and consequently in a decrease of the surface potentials fr, because the charge densities remain constant. The ISFET will measure a transient change in the mean pore potential. As a result of the potential changes, an ion redistribution will take place and the equilibrium situation is re-established. The theoretical maximum ion step response is the change in the mean pore potential. This is comparable with the Donnan model where the theoretical maximum is determined by the change in the Donnan potential at the membrane solution interface. 

Liltration evaluations may involve analytical membranes, particle-loading tests, measurement of gel content or tail-end large-particle mass concentration, and the effects of filtration on oxidizer and organic... 

Marzesco, A.M., Janich, R, Wilsch-Brauninger, M., Dubreuil, V, Langenfeld, K., Corbeil, D. and Huttner, W.B. (2005) Release of extracellular membrane particles carrying the stem cell marker prominin-1 (CD133) from neural progenitors and other epithelial cells. J. Cell Sci. 118, 2849-2858. 

In the pharmaceutical industry, most of the critical membrane filtration operations, such as sterile and virus filtration, are performed in the direct flow filtration mode where a feed solution passes directly through a membrane. As the solution passes through the membrane, particles are retained by size exclusion or adsorption. Direct flow filtration can be operated under constant flow or constant pressure modes. 

Nystrbm M, Pihlajamaki A, Liikanen R, and Manttari M. Influence of process conditions and membrane/particle interactions in NF of wastewaters. Desalination 2003 156 379-387. 

Membrane particles were isolated by high speed centrifugation, resuspended in 50 mM Tris-HCl (pH 8.0), 250 mM NaCl and sedimented again at high speed. Membrane pellets were stored frozen. 

Note that LHCll is a separate light-harvesting complex, which supplements the inner antennae (CP29, CP26, CP24 and CP22) associated with the PS-II complex. The presence of this separate LHC II complex has been confirmed by the results of freeze-fracture experiments obtained with thylakoid membranes of both wild-type and mutant plants. The PS-11 inner antenna complex and the LHC-II complex appear as distinctly different classes of membrane particles. On the other hand, the LHC-I proteins associated with the PS-1 complex appear to be complexed to the PS-1 reaction center, much as the inner antennae of PS II are complexed to the PS-II reaction center. 

---