scholarly journals Lipids of the ultra-thin square halophilic archaeonHaloquadratum walsbyi

Archaea ◽  
2008 ◽  
Vol 2 (3) ◽  
pp. 177-183 ◽  
Author(s):  
Simona LoBasso ◽  
Patrizia LoPalco ◽  
Giuseppe Mascolo ◽  
Angela Corcelli

The lipid composition of the extremely halophilic archaeonHaloquadratum walsbyiwas investigated by thin-layer chromatography and electrospray ionization-mass spectrometry. The analysis of neutral lipids showed the presence of vitamin MK-8, squalene, carotene, bacterioruberin and several retinal isomers. The major polar lipids were phosphatidylglycerophosphate methyl ester, phosphatidylglycerosulfate, phosphatidylglycerol and sulfated diglycosyl diether lipid. Among cardiolipins, the tetra-phytanyl or dimeric phospholipids, only traces of bisphosphatidylglycerol were detected. When the cells were exposed to hypotonic medium, no changes in the membrane lipid composition occurred. Distinguishing it from other extreme halophiles of the Halobacteriaceae family, the osmotic stress did not induce the neo-synthesis of cardiolipins inH. walsbyi. The difference may depend on the three-laminar structure of the cell wall, which differs significantly from that of other Haloarchaea.

1999 ◽  
Vol 276 (1) ◽  
pp. H149-H158 ◽  
Author(s):  
Salvatore Pepe ◽  
Naotaka Tsuchiya ◽  
Edward G. Lakatta ◽  
Richard G. Hansford

Aberrations in cell Ca2+ homeostasis have been known to parallel both changes in membrane lipid composition and aging. Previous work has shown that the lowered efficiency of work performance, which occurs in isolated hearts from rats fed a diet rich in n–6 polyunsaturated fatty acids (PUFA), relative to those fed n–3 PUFA, could be raised by mitochondrial (Mito) Ca2+ transport inhibition. We tested whether, after Ca2+-dependent stress, the Ca2+-dependent activation of pyruvate dehydrogenase (PDHA/PDHTotal) and Mito Ca2+ cycling could be manipulated by varying the ratio of n–3 to n–6 PUFA in Mito membranes in young (6 mo) and aged (24 mo) isolated rat hearts treated to n–3 or n–6 PUFA-rich diet. Inotropic stimulation by 1 μM norepinephrine (NE) of 24-mo n–6 PUFA-rich hearts elevated total Mito Ca2+ content 38% more than in 6-mo hearts ( P < 0.05). However, both the NE-induced rise in Mito Ca2+ and the difference in response between 6- and 24-mo hearts were partially abolished by n–3 PUFA treatment. NE increased the fractional activation of PDH by 44% above control levels in the 6-mo group compared with 49% in the 24-mo group after n–6 PUFA diet. However, NE stimulation of PDHA was attenuated by n–3 PUFA diet, attaining values only 29 and 23% above control levels in 6- and 24-mo mitochondria, respectively ( P < 0.05). Global ischemia and reperfusion (I/R) in n–6 PUFA hearts gave rise to higher levels of total Mito Ca2+concentration ( P < 0.0001) and PDHA( P < 0.0001) compared with n–3 PUFA. Ruthenium red (3.4 μM) abolished the effects of I/R in all groups. With aging, heart Mito membrane phosphatidylcholine was increased after n–6 PUFA-rich diet (by ∼15%, P < 0.05), whereas cardiolipin and n–3 PUFA content were diminished by 31% ( P < 0.05) and 73% ( P < 0.05), respectively. These effects were prevented by n–3 PUFA-rich diet. The present study, by directly manipulating the cardiac Mito membrane n–3-to-n–6 PUFA ratio, shows that the activation of Ca2+-dependent PDH can be augmented when the n–3-to-n–6 PUFA ratio is low (n–6 PUFA-rich diet; 24-mo hearts) or attenuated when this ratio is relatively high (n–3 PUFA-rich diet). We propose that one of the consequences of dietary-induced manipulation of membrane phospholipids and PUFAs may be the altered flux of Ca2+ across the Mito membrane and thus altered intramitochondrial Ca2+-dependent processes.


Author(s):  
V.A. Korolev ◽  
O.A. Medvedeva ◽  
A.D. Bogomazov ◽  
N.A. Verevkina ◽  
I.V. Korolev

The erythrocyte membrane is a user-friendly model, since its structural is similar to that of molecular structure of plasma membranes. Therefore, the slightly corrected patterns of changes in the structure and functions of the erythrocyte membrane can be transferred to other membrane systems. Changes in the structure of membrane lipids under various factors are of great importance for the functional state of both the membranes themselves and the body as a whole. In diseases with severe hypoxic syndrome, changes in the membrane structure are the most obvious ones. These disorders can be observed under exposure to various drugs, namely, broad-spectrum antibiotics. The aim of the paper is to study the lipid composition of erythrocyte membranes under gentamicin-associated dysbiosis and to correct it with the B. Bifidum. Materials and Methods. The study was conducted on 60 BALB/c mice (18–20 g.). The animals were divided into three groups, 20 animals in each. The first group is a control one (intact mice). The second group consisted of animals with modeled gentamicin-associated dysbiosis. Animals of the third group were treated with Bifidum BAG Probiotic (21 days, once a day) after the formation of fixed drug dysbiosis. Traditional methods were used to determine the lipid composition of red blood cells. Chromatography was performed according to V.I. Krylov method. Results. To correct pathological conditions, the authors used Bifidum BAG probiotic, which consists of living active bifidobacteria B. bifidum, B. longum, and powerful plant antioxidant, dihydroquercetin. Administration of a broad-spectrum antibiotic (gentamicin) resulted in a significant change in the quantitative composition of neutral lipids and phospholipids. Intake of a complex probiotic led to the membrane lipid spectrum correction. Conclusion. It is established that Bifidum BAG probiotic leads to a normalization of the erythrocyte membrane lipid spectrum with gentamicin-associated dysbiosis, which may be associated with the antioxidant, membrane-stabilizing and antihypoxic effect of the drug. Keywords: dysbiosis, phospholipids, neutral lipids, erythrocyte membrane, Bifidum BAG. Эритроцитарная мембрана является удобным модельным объектом, так как имеет общие принципы строения с молекулярной структурой плазматических мембран, поэтому закономерности изменений структуры и функций мембраны эритроцитов с незначительной долей коррекции могут быть перенесены на другие мембранные системы. Изменения в структуре липидов мембран под влиянием различных факторов имеют большое значение для функционального состояния как самих мембран, так и организма в целом. При заболеваниях, которые протекают с выраженным гипоксическим синдромом, изменения структуры мембраны наиболее выражены. Эти нарушения могут наблюдаться при воздействии различных лекарственных препаратов, в т.ч. антибиотиков широкого спектра действия. Целью исследования явилось изучение состава липидов мембран эритроцитов в условиях гентамицинассоциированного дисбиоза и коррекции его комплексным препаратом «Бифидум БАГ». Материалы и методы. Исследование проведено на 60 мышах линии BALB/c с массой 18–20 г. Животные были разделены на три группы по 20 особей в каждой. Первая группа – контрольная (интактные мыши). Вторую группу составили животные, которым моделировали гентамицинассоциированный дисбиоз. Животные третьей группы интрагастрально получали комплексный пробиотик «Бифидум БАГ» в течение 21 дня 1 раз в сутки после формирования стойкого лекарственного дисбактериоза. Липидный состав эритроцитов определяли традиционными методами. Хроматографирование проводили по методу В.И. Крылова. Результаты. Для коррекции патологических состояний использовали комплексный препарат «Бифидум БАГ», в состав которого, помимо живых активных видов бифидобактерий B. bifidum и B. Longum, входит растительный антиоксидант – дигидрокверцетин. Применение антибиотика широкого спектра действия (гентамицина) привело к значительному изменению количественного состава нейтральных липидов и фосфолипидов. Введение комплексного пробиотика привело к коррекции спектра липидов мембран. Выводы. Установлено, что комплексный препарат «Бифидум БАГ» приводит к нормализации спектра липидов мембран эритроцитов при гентамицинассоциированном дисбиозе, что может быть связано с антиоксидантным, мембраностабилизирующим и антигипоксическим действием препарата. Ключевые слова: дисбиоз, фосфолипиды, нейтральные липиды, мембрана эритроцита, «Бифидум БАГ».


1982 ◽  
Vol 48 (01) ◽  
pp. 049-053 ◽  
Author(s):  
C G Fenn ◽  
J M Littleton

SummaryEthanol at physiologically tolerable concentrations inhibited platelet aggregation in vitro in a relatively specific way, which may be influenced by platelet membrane lipid composition. Aggregation to collagen, calcium ionophore A23187 and thrombin (low doses) were often markedly inhibited by ethanol, adrenaline and ADP responses were little affected, and aggregation to exogenous arachidonic acid was actually potentiated by ethanol. Aggregation to collagen, thrombin and A23187 was inhibited more by ethanol in platelets enriched with saturated fatty acids than in those enriched with unsaturated fats. Platelets enriched with cholesterol showed increased sensitivity to ADP, arachidonate and adrenaline but this increase in cholesterol content did not appear to influence the inhibition by ethanol of platelet responses. The results suggest that ethanol may inhibit aggregation by an effect on membrane fluidity and/or calcium mobilization resulting in decreased activity of a membrane-bound phospholipase.


2012 ◽  
pp. 84-89
Author(s):  
Quoc Hung Vo ◽  
Nguyen Phuong Nhi Doan ◽  
Dinh Quynh Phu Nguyen ◽  
Thi Dieu Tram Ho ◽  
Thi Hoai Nguyen

Objectives: Nowadays, bioactive substances isolated from marine organisms which are abundant and varied in Vietnamese sea attracted more and more the attention of scientists in the world and Vietnam as well. We have studied on soft coral Sinularia cruciata – Alcyoniidae, which has never been studied in Vietnam before, to find substances which are useful in medical field, especially in anti-cancer therapy. Materials and method: Specimens of soft coral Sinularia cruciata were collected from Con Co, Quang Tri province in May 2011. Pure compounds were isolated by using Thin Layer Chromatography; Column Chromatography normal phase and inverse phase; Shephadex LH 20. Structures of them were determined by spectral data of Nuclear Magnetic Resonance (NMR), Electrospray Ionization Mass Spectrometry (ESI-MS). Results & Conclusion: Structures of 4 compounds were identified: (1) 5.8-epidioxycholest-6-en-3-ol (2) Cholesterol (3) 1-O-hexadecyl-glycerol (Chimyl alcohol) (4) Glycerol 1-O-octadecyl ether (Batyl alcohol). The substance (1) was demonstrated to have strong anti-cancer effects in previous study. Key words Sinularia cruciata, Alcyoniidae, 5,8-epidioxycholest-6-en-3-ol, soft coral, cancer.


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