Dataset Information

Importance of the sphingoid base length for the membrane properties of ceramides.

ABSTRACT: The sphingoid bases of sphingolipids, including ceramides, can vary in length from 12 to >20 carbons. To study how such length variation affects the bilayer properties of ceramides, we synthesized ceramides consisting of a C12-, C14-, C16-, C18-, or C20-sphing-4-enin derivative coupled to palmitic acid. The ceramides were studied in mixtures with palmitoyloleoylphosphocholine (POPC) and/or palmitoylsphingomyelin (PSM), and in more complex bilayers also containing cholesterol. The trans-parinaric acid lifetimes showed that 12:1- and 14:1-PCer failed to increase the order of POPC bilayers, whereas 16:1-, 18:1-, and 20:1-PCer induced ordered- or gel-phase formation. Nevertheless, all of the analogs were able to thermally stabilize PSM, and a chain-length-dependent increase in the main phase transition temperature of equimolar PSM/Cer bilayers was revealed by differential scanning calorimetry. Similar thermal stabilization of PSM-rich domains by the ceramides was observed in POPC bilayers with a trans-parinaric acid-quenching assay. A cholestatrienol-quenching assay and sterol partitioning experiments showed that 18:1- and 20:1-PCer formed sterol-excluding gel phases with PSM, reducing the overall bilayer affinity of sterol. The effect of 16:1-PCer on sterol distribution was less dramatic, and no displacement of sterol from the PSM environment was observed with 12:1- and 14:1-PCer. The results are discussed in relation to other structural features that affect the bilayer properties of ceramides.

SUBMITTER: Maula T

PROVIDER: S-EPMC3491676 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Importance of the sphingoid base length for the membrane properties of ceramides.

Maula Terhi T Artetxe Ibai I Grandell Pia-Maria PM Slotte J Peter JP

Biophysical journal 20121101 9

The sphingoid bases of sphingolipids, including ceramides, can vary in length from 12 to >20 carbons. To study how such length variation affects the bilayer properties of ceramides, we synthesized ceramides consisting of a C12-, C14-, C16-, C18-, or C20-sphing-4-enin derivative coupled to palmitic acid. The ceramides were studied in mixtures with palmitoyloleoylphosphocholine (POPC) and/or palmitoylsphingomyelin (PSM), and in more complex bilayers also containing cholesterol. The trans-parinaric ...[more]

PMID: 23199915

Similar Datasets

Project description:Inositol phosphorylceramide (IPC), the major sphingolipid in the genus Leishmania but not found in mammals, is considered a potentially useful target for chemotherapy against leishmaniasis. Leishmania (Viannia) braziliensis is endemic in Latin America and causes American tegumentary leishmaniasis. We demonstrated that IPCs are localized internally in parasites, using a specific monoclonal antibody. Treatment with 5 μM myriocin (a serine palmitoyltransferase inhibitor) rendered promastigotes 8-fold less infective than controls in experimental hamster infection, as determined by number of parasites per inguinal lymph node after 8 weeks infection, suggesting the importance of parasite IPC or sphingolipid derivatives in parasite infectivity or survival in the host. IPC was isolated from promastigotes of three L. (V.) braziliensis strains and analyzed by positive- and negative-ion ESI-MS. The major IPC ions were characterized as eicosasphinganine and eicosasphingosine. Negative-ion ESI-MS revealed IPC ion species at m/z 778.6 (d20:1/14:0), 780.6 (d20:0/14:0), 796.6 (t20:0/14:0), 806.6 (d20:1/16:0), and 808.6 (d20:0/16:0). IPCs isolated from L. (V.) braziliensis and L. (L.) major showed significant differences in IPC ceramide composition. The major IPC ion from L. (L.) major, detected in negative-ion ESI-MS at m/z 780.6, was composed of ceramide d16:1/18:0. Our results suggest that sphingosine synthase (also known as serine palmitoyltransferase; SPT) in L. (V.) braziliensis is responsible for synthesis of a long-chain base of 20 carbons (d20), whereas SPT in L. (L.) major synthesizes a 16-carbon long-chain base (d16). A phylogenetic tree based on SPT proteins was constructed by analysis of sequence homologies in species of the Leishmania and Viannia subgenera. Results indicate that SPT gene position in L. (V.) braziliensis is completely separated from that of members of subgenus Leishmania, including L. (L.) major, L. (L.) infantum, and L. (L.) mexicana. Our findings clearly demonstrate sphingoid base differences between L. (V.) braziliensis and members of subgenus Leishmania, and are relevant to future development of more effective targeted anti-leishmaniasis drugs.

Dataset Information

Importance of the sphingoid base length for the membrane properties of ceramides.

Publications

Importance of the sphingoid base length for the membrane properties of ceramides.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets