scholarly journals Asymmetric reassociation of calf spleen NAD+ glycohydrolase into liposomes

1987 ◽  
Vol 246 (2) ◽  
pp. 319-324 ◽  
Author(s):  
H M Muller ◽  
F Schuber
Keyword(s):  
Outer Surface ◽  
Active Site ◽  
Gel Filtration ◽  
Water Soluble ◽  
Unilamellar Vesicles ◽  
Phosphatidylcholine Liposomes ◽  
Nad Glycohydrolase ◽  
Large Unilamellar Vesicles ◽  
Solubilized Enzyme

NAD+ glycohydrolase (NAD+ nucleosidase, EC 3.2.2.6) can be solubilized from calf spleen microsomes (microsomal fractions) by steapsin or by detergents to yield respectively a hydrophilic (i.e. water-soluble) and a hydrophobic form of the enzyme. The detergent-solubilized enzyme was successfully reassociated into phosphatidylcholine liposomes either by a cholate-dialysis or by a gel-filtration procedure. In both cases the incorporation of NAD+ glycohydrolase was found to be completely asymmetric, i.e. the active site of the enzyme was exposed only at the outer surface of the vesicles. By contrast, as judged by flotation experiments, the hydrophilic form of NAD+ glycohydrolase could not be reassociated into liposomes. These results are in agreement with the hypothesis that calf spleen NAD+ glycohydrolase is an amphipathic protein. When incorporated into large unilamellar vesicles composed of phosphatidylcholine, NAD+ glycohydrolase was not found to catalyse vectorial transfer of NAD+ by transglycosidation with nicotinamide as acceptor.

A novel antioxidant action of ethanolamine plasmalogens in lowering the oxidizability of membranes

2004 ◽  
Vol 32 (1) ◽  
pp. 141-143 ◽  
Author(s):  
R. Maeba ◽  
N. Ueta
Keyword(s):  
Free Radicals ◽  
Oxygen Uptake ◽  
Water Soluble ◽  
Antioxidant Action ◽  
Unilamellar Vesicles ◽  
Radical Initiator ◽  
Large Unilamellar Vesicles ◽  
Ethanolamine Plasmalogens ◽  
Uptake Method

We have demonstrated a novel antioxidant action of ethanolamine plasmalogens both in protecting cholesterol from oxidation by free radicals and in lowering the oxidizability of membranes, along with the action of scavenging radicals, by the oxygen-uptake method using large unilamellar vesicles and the water-soluble azo-radical initiator, AAPH [2,2´-azobis-(2-amidino-propane) dihydrochloride].

Turnover of Human Extrinsic (Tissue-Type) Plasminogen Activator in Rabbits

1981 ◽  
Vol 46 (03) ◽  
pp. 658-661 ◽  
Author(s):  
C Korninger ◽  
J M Stassen ◽  
D Collen
Keyword(s):  
Plasminogen Activator ◽  
Intravenous Injection ◽  
Active Site ◽  
Half Life ◽  
Degradation Products ◽  
Gel Filtration ◽  
Tissue Type ◽  
Organ Distribution ◽  
Small Rise

SummaryThe turnover of highly purified human extrinsic plasminogen activator (EPA) (one- and two-chain form) was studied in rabbits. Following intravenous injection, EPA-activity declined rapidly. The disappearance rate of EPA from the plasma could adequately be described by a single exponential term with a t ½ of approximately 2 min for both the one-chain and two-chain forms of EPA.The clearance and organ distribution of EPA was studied by using 125I-labeled preparations. Following intravenous injection of 125I-1abeled EPA the radioactivity disappeared rapidly from the plasma also with a t ½ of approximately 2 min down to a level of 15 to 20 percent, followed by a small rise of blood radioactivity. Gel filtration of serial samples revealed that the secondary increase of the radioactivity was due to the reappearance of radioactive breakdown products in the blood. Measurement of the organ distribution of 125I at different time intervals revealed that EPA was rapidly accumulated in the liver, followed by a release of degradation products in the blood.Experimental hepatectomy markedly prolonged the half-life of EPA in the blood. Blocking the active site histidine of EPA had no effect on the half-life of EPA in blood nor on the gel filtration patterns of 125I in serial plasma samples.It is concluded that human EPA is rapidly removed from the blood of rabbits by clearance and degradation in the liver. Recognition by the liver does not require a functional active site in the enzyme. Neutralization in plasma by protease inhibitors does not represent a significant pathway of EPA inactivation in vivo.

scholarly journals α-Synuclein Binds Large Unilamellar Vesicles as an Extended Helix†

Biochemistry ◽  
2009 ◽  
Vol 48 (11) ◽  
pp. 2304-2306 ◽  
Author(s):  
Adam J. Trexler ◽  
Elizabeth Rhoades
Keyword(s):  
Unilamellar Vesicles ◽  
Large Unilamellar Vesicles

Evolution of the thermotropic properties of large unilamellar vesicles (LUV)

1984 ◽  
Vol 40 (7) ◽  
pp. 715-717 ◽  
Author(s):  
M. Vandenbranden ◽  
C. Stil ◽  
R. Brasseur ◽  
J. -M. Ruysschaert
Keyword(s):  
Unilamellar Vesicles ◽  
Large Unilamellar Vesicles ◽  
Thermotropic Properties

The Efficacies of Cell-Penetrating Peptides in Accumulating in Large Unilamellar Vesicles Depend on their Ability To Form Inverted Micelles

ChemBioChem ◽  
2014 ◽  
Vol 15 (6) ◽  
pp. 884-891 ◽  
Author(s):  
Jean-Marie Swiecicki ◽  
Annika Bartsch ◽  
Julien Tailhades ◽  
Margherita Di Pisa ◽  
Benjamin Heller ◽  
...  
Keyword(s):  
Cell Penetrating Peptides ◽  
Unilamellar Vesicles ◽  
Large Unilamellar Vesicles ◽  
Cell Penetrating

scholarly journals Snake venom NAD glycohydrolases: primary structures, genomic location, and gene structure

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6154 ◽  
Author(s):  
Ivan Koludarov ◽  
Steven D. Aird
Keyword(s):  
Snake Venom ◽  
Active Site ◽  
Disulfide Bonds ◽  
Venom Gland ◽  
Catalytic Residue ◽  
Nad Glycohydrolase ◽  
Adp Ribosyl Cyclase ◽  
Genomic Location ◽  
Cyclic Adp Ribose ◽  
Very High

NAD glycohydrolase (EC 3.2.2.5) (NADase) sequences have been identified in 10 elapid and crotalid venom gland transcriptomes, eight of which are complete. These sequences show very high homology, but elapid and crotalid sequences also display consistent differences. As in Aplysia kurodai ADP-ribosyl cyclase and vertebrate CD38 genes, snake venom NADase genes comprise eight exons; however, in the Protobothrops mucrosquamatus genome, the sixth exon is sometimes not transcribed, yielding a shortened NADase mRNA that encodes all six disulfide bonds, but an active site that lacks the catalytic glutamate residue. The function of this shortened protein, if expressed, is unknown. While many vertebrate CD38s are multifunctional, liberating both ADP-ribose and small quantities of cyclic ADP-ribose (cADPR), snake venom CD38 homologs are dedicated NADases. They possess the invariant TLEDTL sequence (residues 144–149) that bounds the active site and the catalytic residue, Glu228. In addition, they possess a disulfide bond (Cys121–Cys202) that specifically prevents ADP-ribosyl cyclase activity in combination with Ile224, in lieu of phenylalanine, which is requisite for ADPR cyclases. In concert with venom phosphodiesterase and 5′-nucleotidase and their ecto-enzyme homologs in prey tissues, snake venom NADases comprise part of an envenomation strategy to liberate purine nucleosides, and particularly adenosine, in the prey, promoting prey immobilization via hypotension and paralysis.

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