Biochemistry of inositol lipids

Abstract

Nature has created an immense combinatorial and structural heterogeneity among lipids. It is becoming increasingly accepted that the vast range of unique chemical entities encodes for distinct functions within biological systems. A unique group of lipids which stands out in terms of diversity as well as biological activity are inositol-containing lipids. The most well characterized inositol lipids are the phosphoinositides, phosphorylated derivatives of glycerophosphoinositol, which play a wide variety of cellular roles in many eukaryotic cells. Less well understood are ceramides containing inositol in fungi, and inositol glycolipids in pathogens. Here we review biochemical aspects of inositol-containing lipids with a focus on novel analytical procedures for their characterization.

Assessment of Changes in Lipid Profile of Pregnant Women during Periods of Gestation and Post Partum in Chotanagpur – A Descriptive Study

“…Although the exact mechanism for the more sensitive regulation of appetite in pregnancy is still not known fully, a more important is that the increases in the adipose tissue store anticipates the late gestation foetal growth spurt by beginning in early gestation and reaching a maximum in mid gestation. 13,14 The importance attached to need for routine examination of serum lipid profile in human subjects especially during pregnancy is well known. The maternal lipid metabolism is specifically altered in pregnancy, with raised lipoprotein and cholesterol levels during different trimesters of pregnancy.…”

The glycerophosphoinositols: cellular metabolism and biological functions

“…1, box), with the production of diacylglycerol and inositol 1,4,5-trisphosphate [3]; and class I phosphoinositide Phospholipase cleavage sites (box phospholipase B, PLB, has both PLA 1 and PLA 2 activities) and schematic representation of the formation of LysoPtdIns and GroPIns from PtdIns via two sequential steps catalysed by PLA 2 IVa, and the subsequent catabolism of GroPIns as mediated by the GDEs (see text for details), AA arachidonic acid, FA generic fatty acid [25] 3-kinase on the other, with the production of phosphatidylinositol 3,4,5-trisphosphate (PtdIns345P 3 ) [4]. These main PtdIns45P 2 metabolites are the primary second messengers for activation of numerous enzyme systems devoted to the modulation of intracellular calcium signalling, further soluble inositol polyphosphate production [5], protein phosphorylation cascades [6] and further membrane polyphosphoinositide lipid production [7]; these last, in turn, regulate cellular functions or provide docking sites for lipid-binding proteins [8].…”

“…The examples given above represent only a fraction of the growing body of information on the metabolism and functions of the lipid-derived messengers: we thus refer the readers to recent reviews addressing these different classes of lipids and lipid-derived compounds [1,2,7]. Here, instead, as indicated above, our aim is to focus on the glycerophosphoinositols as a specific class of phosphoinositide metabolites.…”

Sphingolipidomics: An Important Mechanistic Tool for Studying Fungal Pathogens

“…The fatty acyl moiety of the phytoceramides is α-hydroxylated by a sphingolipid α-hydroxylase to form αOH-phytoceramides ( Haak et al, 1997 ). Both phytoceramides and αOH-phytoceramides are further converted to complex phosphosphingolipids such as IPC (transfer of phosphorylinositol group to phytoceramide), MIPC, (transfer of mannosyl group to IPC) and M(IP) 2 C, (transfer of a second phosphorylinositol group to MIPC; Guan and Wenk, 2008 ). Although IPC derivatives are not reported in mammals, certain plants and kinetoplastid protozoa do produce IPC derivatives ( Heung et al, 2006 ).…”