Membrane Transport - Austin Publishing Group
... Due to this lack of resistance, passive transport does not require any input of energy. Both carrier and channel proteins permit passive transport by facilitating the selective diffusion of solute molecules with their concentration gradient, termed facilitated diffusion. Porins are beta barrel chann ...
... Due to this lack of resistance, passive transport does not require any input of energy. Both carrier and channel proteins permit passive transport by facilitating the selective diffusion of solute molecules with their concentration gradient, termed facilitated diffusion. Porins are beta barrel chann ...
Thylakoid biogenesis has joined the new era of bacterial cell biology
... Umena et al., 2011). They are composed of dozens of protein subunits as well as hundreds of organic and inorganic co-factors, most of which are embedded in the lipid bilayer of thylakoid membranes. Despite this profound knowledge on the architecture and function of the thylakoid membrane relatively ...
... Umena et al., 2011). They are composed of dozens of protein subunits as well as hundreds of organic and inorganic co-factors, most of which are embedded in the lipid bilayer of thylakoid membranes. Despite this profound knowledge on the architecture and function of the thylakoid membrane relatively ...
Defining new SNARE functions: the i-SNARE
... SNAREs (N-ethylmaleimide-sensitive factor adaptor protein receptors) have been often seen to have a dishomogeneous distribution on membranes and are apparently present in excess of the amount required to assure correct vesicle traffic. It was also shown in few cases that SNARE on the target membrane ...
... SNAREs (N-ethylmaleimide-sensitive factor adaptor protein receptors) have been often seen to have a dishomogeneous distribution on membranes and are apparently present in excess of the amount required to assure correct vesicle traffic. It was also shown in few cases that SNARE on the target membrane ...
Encontro de Jovens Investigadores de Biologia Computacional
... the biophysical aspects of drug efflux by P-gp still remain largely unknown. Following our characterization of three drug-binding sites within P-gp\'s internal drug-binding pocket (DBP), a series of molecular dynamics studies were performed using a refined P-gp structure to further clarify how drug ...
... the biophysical aspects of drug efflux by P-gp still remain largely unknown. Following our characterization of three drug-binding sites within P-gp\'s internal drug-binding pocket (DBP), a series of molecular dynamics studies were performed using a refined P-gp structure to further clarify how drug ...
Membrane Topology of Cytochrome P450 2B4 in
... as well as to physiologically occurring compounds such as retinoids, steroids, and prostaglandins, has made this class of heme–monoxygenases the target of a wide range of structure–function investigations. Unfortunately, the vast majority of cytochromes P450 are membrane proteins that are not easily ...
... as well as to physiologically occurring compounds such as retinoids, steroids, and prostaglandins, has made this class of heme–monoxygenases the target of a wide range of structure–function investigations. Unfortunately, the vast majority of cytochromes P450 are membrane proteins that are not easily ...
STRUCTURE-FUNCTION RELATIONSHIPS IN
... evolution . Structural responses of the isolated adipose cell to hormones, if such occur, must, therefore, be dynamic rather than qualitative in nature ; the extensive system of smooth surfaced membranes is suggestive of compartmentalized transport and metabolism. INTRODUCTION The mature white adipo ...
... evolution . Structural responses of the isolated adipose cell to hormones, if such occur, must, therefore, be dynamic rather than qualitative in nature ; the extensive system of smooth surfaced membranes is suggestive of compartmentalized transport and metabolism. INTRODUCTION The mature white adipo ...
Lysophospholipids and fat digestibility
... If lysophospholipids are added to the diet, the intestinal absorption profile is altered by an increase in passive transport. If more lysophospholipids are not added, acyltransferase activity will return the lysomolecules to its diacyl form and the cell will return to equilibrium. This is a key appl ...
... If lysophospholipids are added to the diet, the intestinal absorption profile is altered by an increase in passive transport. If more lysophospholipids are not added, acyltransferase activity will return the lysomolecules to its diacyl form and the cell will return to equilibrium. This is a key appl ...
Minireview: Lipid Droplets in Lipogenesis and Lipolysis
... proposed that a major function of the adipocyte-secreted hormone leptin is to prevent ectopic lipid accumulation in nonadipocytes at least in part by promoting fatty acid oxidation and preventing induction of lipogenesis in muscle and liver (8). The storage of lipid in nonadipocytes in and of itself ...
... proposed that a major function of the adipocyte-secreted hormone leptin is to prevent ectopic lipid accumulation in nonadipocytes at least in part by promoting fatty acid oxidation and preventing induction of lipogenesis in muscle and liver (8). The storage of lipid in nonadipocytes in and of itself ...
Plant physiology
... As noted above, the identity of the fatty acids at the sn-2 position in higher plants is considered as an indicator for its origin: 18C when made in the ER or 16C when made in the chloroplast. To test the applicability of this criterion to Dunaliella lipids, we analyzed the fatty acid compositions a ...
... As noted above, the identity of the fatty acids at the sn-2 position in higher plants is considered as an indicator for its origin: 18C when made in the ER or 16C when made in the chloroplast. To test the applicability of this criterion to Dunaliella lipids, we analyzed the fatty acid compositions a ...
Chapter 05 Membranes
... have additional molecules attached, such as the positively charged choline ( green) shown. Phosphatidylcholine is a common component of membranes. It is shown in (a) with its chemical formula, (b) as a space-filling model, and (c) as the icon that is used in most of the figures in this ...
... have additional molecules attached, such as the positively charged choline ( green) shown. Phosphatidylcholine is a common component of membranes. It is shown in (a) with its chemical formula, (b) as a space-filling model, and (c) as the icon that is used in most of the figures in this ...
Studies on Liver Plasma Membranes of Rats Fed
... properties of the floating fraction (obtained in a subsequent experiment) are summarized in Table 4. The floating layer was characterized by fairly high activities of 5'-nucleotidase and ATPase and low activities of glucose 6-phophatase and succinic dehydrogenase. However, the lipid:protein ratio wa ...
... properties of the floating fraction (obtained in a subsequent experiment) are summarized in Table 4. The floating layer was characterized by fairly high activities of 5'-nucleotidase and ATPase and low activities of glucose 6-phophatase and succinic dehydrogenase. However, the lipid:protein ratio wa ...
Vesicles: Equal in Neurotransmitter Concentration but Not in Volume
... there is shear between them at the level of the stereocilia. When the basilar membrane moves down, the stereocilia are pulled one way (to the left in the figure); as it moves up in the next half-cycle, the stereocilia are pushed to the right. Stereocilia deflection opens transduction channels to cau ...
... there is shear between them at the level of the stereocilia. When the basilar membrane moves down, the stereocilia are pulled one way (to the left in the figure); as it moves up in the next half-cycle, the stereocilia are pushed to the right. Stereocilia deflection opens transduction channels to cau ...
What is “membrane potential”
... A, Draw a diagram of the endosome showing the two transporters and the movement of ions. B. Why does a mutation to the Cl- pump impair endosome acidification? C. Could a Ca++ pump substitute for the Cl- pump? Why or why not? ...
... A, Draw a diagram of the endosome showing the two transporters and the movement of ions. B. Why does a mutation to the Cl- pump impair endosome acidification? C. Could a Ca++ pump substitute for the Cl- pump? Why or why not? ...
Figure S1. Chloroplast localization and topology of TerC
... Figure S1. Chloroplast localization and topology of TerC-GFP fusion protein. (a) Protoplasts were isolated from terc-1TerC-GFP. Chlorophyll fluorescence was excited at 450 – 490 nm and the emission was recorded at > 515 nm (Filterset 9, Carl Zeiss, http://microscopy.zeiss.com/microscopy/en_de/servic ...
... Figure S1. Chloroplast localization and topology of TerC-GFP fusion protein. (a) Protoplasts were isolated from terc-1TerC-GFP. Chlorophyll fluorescence was excited at 450 – 490 nm and the emission was recorded at > 515 nm (Filterset 9, Carl Zeiss, http://microscopy.zeiss.com/microscopy/en_de/servic ...
The Parkinson`s disease protein -synuclein disrupts
... directed against GFP. !-Syn-GFP fusions can behave aberrantly in mammalian cells, but these problems do not occur in yeast. The fusion protein was not cleaved (data not shown), and its biology was identical to untagged !-syn (10). ImmunoEM requires a compromise between mild fixation, needed to prese ...
... directed against GFP. !-Syn-GFP fusions can behave aberrantly in mammalian cells, but these problems do not occur in yeast. The fusion protein was not cleaved (data not shown), and its biology was identical to untagged !-syn (10). ImmunoEM requires a compromise between mild fixation, needed to prese ...
Membrane protein integration into the endoplasmic reticulum
... of them containing charged residues [49–51]. These observations, together with the fact that TRAM itself contains an unusually high number of charged residues within its TM segments, led to the idea that TRAM could act as a chaperone for the integration of nonoptimal TM segments by providing a more ...
... of them containing charged residues [49–51]. These observations, together with the fact that TRAM itself contains an unusually high number of charged residues within its TM segments, led to the idea that TRAM could act as a chaperone for the integration of nonoptimal TM segments by providing a more ...
Article Integrin-Dependent Organization and Bidirectional Vesicular Traffic at Cytotoxic Immune Synapses Immunity
... To test whether degranulation was induced by ligands on lipid bilayers, we included a directly labeled Fab of a CD107a mAb in the lipid bilayer chamber and imaged it by TIRF microscopy, as described (Beal et al., 2008). The assay was first validated with NK cells stimulated by Phorbol 12-myristate 1 ...
... To test whether degranulation was induced by ligands on lipid bilayers, we included a directly labeled Fab of a CD107a mAb in the lipid bilayer chamber and imaged it by TIRF microscopy, as described (Beal et al., 2008). The assay was first validated with NK cells stimulated by Phorbol 12-myristate 1 ...
Junior team leader positions at the IBS
... instruments to analyze membrane proteins. The successful candidate should have experience in X-ray crystallography and/or single particle electron microscopy of membrane proteins and should propose a project relevant to one of the three main research axes of the IBS with a strong focus on structure- ...
... instruments to analyze membrane proteins. The successful candidate should have experience in X-ray crystallography and/or single particle electron microscopy of membrane proteins and should propose a project relevant to one of the three main research axes of the IBS with a strong focus on structure- ...
Concentration gradient
... – transport substances much more slowly across a membrane compared to channels • the maximum rate at which these proteins can transport substances across a membrane is limited by how fast they can change shapes • Pumps hydrolyze a molecule of ATP and use the energy to transport substances across the ...
... – transport substances much more slowly across a membrane compared to channels • the maximum rate at which these proteins can transport substances across a membrane is limited by how fast they can change shapes • Pumps hydrolyze a molecule of ATP and use the energy to transport substances across the ...
Apolipophorins and insects immune response
... apoLp-III molecule is formed by a bundle of five antiparallel amphipathic α-helices organized in an up-and-down topology, which are connected by short hinged loop regions (Breiter et al., 1991). This bundle motif is a stable arrangement of the protein, which allows it to exist in hemolymph. A majori ...
... apoLp-III molecule is formed by a bundle of five antiparallel amphipathic α-helices organized in an up-and-down topology, which are connected by short hinged loop regions (Breiter et al., 1991). This bundle motif is a stable arrangement of the protein, which allows it to exist in hemolymph. A majori ...
Chapter 7
... • In 1972, J. Singer and G. Nicolson proposed that the membrane is a mosaic of proteins dispersed within the bilayer, with only the hydrophilic regions exposed to water Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings ...
... • In 1972, J. Singer and G. Nicolson proposed that the membrane is a mosaic of proteins dispersed within the bilayer, with only the hydrophilic regions exposed to water Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings ...
assembly of integral membrane proteins from the periplasm into the
... OMPs insert and fold into lipid bilayers by a highly concerted mechanism, in which secondary and tertiary structure formation is synchronized and coupled to lipid bilayer insertion. This chapter summarizes the current knowledge about the transport of OMPs through the periplasm and about their assemb ...
... OMPs insert and fold into lipid bilayers by a highly concerted mechanism, in which secondary and tertiary structure formation is synchronized and coupled to lipid bilayer insertion. This chapter summarizes the current knowledge about the transport of OMPs through the periplasm and about their assemb ...
Lens Major Intrinsic Protein (MIP)
... quenching was obtained by measuring the slope of the first 30 s after the mixing of LUV populations (see Figure 1). This parameter was used to quantify the initial rate of aggregation under various experimental conditions. The effect of pH on the initial rate of quenching at various pH conditions wa ...
... quenching was obtained by measuring the slope of the first 30 s after the mixing of LUV populations (see Figure 1). This parameter was used to quantify the initial rate of aggregation under various experimental conditions. The effect of pH on the initial rate of quenching at various pH conditions wa ...
and extra-vesicular ions and membrane associated charges in
... diether) phospholipids are of great biophysical interest. First, the plasma membranes of crenarchaeota, which include thermoacidophilic archaea, contain primarily BTLs and a small amount of diether lipids [1]. Archaeal BTLs are able to form vesicular membranes where the BTL molecules adopt an up-rig ...
... diether) phospholipids are of great biophysical interest. First, the plasma membranes of crenarchaeota, which include thermoacidophilic archaea, contain primarily BTLs and a small amount of diether lipids [1]. Archaeal BTLs are able to form vesicular membranes where the BTL molecules adopt an up-rig ...
Bacterial Outer Membrane Vesicles as a Delivery System for
... immune response and have been developed into a vaccine formula, Bexsero (Novartis), which was approved in Europe. However, the lack of information on OMV biogenesis hinders modification for large-scale OMV production, and the excessive toxicity of pathogen-derived OMVs prevents their clinical applic ...
... immune response and have been developed into a vaccine formula, Bexsero (Novartis), which was approved in Europe. However, the lack of information on OMV biogenesis hinders modification for large-scale OMV production, and the excessive toxicity of pathogen-derived OMVs prevents their clinical applic ...
Model lipid bilayer
A model lipid bilayer is any bilayer assembled in vitro, as opposed to the bilayer of natural cell membranes or covering various sub-cellular structures like the nucleus. A model bilayer can be made with either synthetic or natural lipids. The simplest model systems contain only a single pure synthetic lipid. More physiologically relevant model bilayers can be made with mixtures of several synthetic or natural lipids.There are many different types of model bilayers, each having experimental advantages and disadvantages. The first system developed was the black lipid membrane or “painted” bilayer, which allows simple electrical characterization of bilayers but is short-lived and can be difficult to work with. Supported bilayers are anchored to a solid substrate, increasing stability and allowing the use of characterization tools not possible in bulk solution. These advantages come at the cost of unwanted substrate interactions which can denature membrane proteins.