Binding lipid

Figure 9 Relative accuracy of comparative models. Upper left panel, comparison of homologous structures that share 40% sequence identity. Upper right panel, conformations of ileal lipid-binding protein that satisfy the NMR restraints set equally well. Lower left panel, comparison of two independently determined X-ray structures of interleukin 1(3. Lower right panel, comparison of the X-ray and NMR structures of erabutoxin. The figure was prepared using the program MOLSCRIPT [236].

A. Ligand Specificity of Brain Lipid-Binding Protein... 

LZ Xu, R Sanchez, A Sail, N Hemtz. Ligand specificity of brain lipid binding protein. I Biol Chem 271 24711-24719, 1996. 

There is a second family of small lipid-binding proteins, the P2 family, which include among others cellular retinol- and fatty acid-binding proteins as well as a protein, P2, from myelin in the peripheral nervous system. However, members of this second family have ten antiparallel p strands in their barrels compared with the eight strands found in the barrels of the RBP superfamily. Members of the P2 family show no amino acid sequence homology to members of the RBP superfamily. Nevertheless, their three-dimensional structures have similar architecture and topology, being up-and-down P barrels. 

Detailed protein structures have been reported for BPI and CETP. Given the aforementioned similarities within this gene family, these protein structures serve as a likely model for the protein structure of PLTP. CETP and BPI are elongated molecules, shaped like a boomerang. There are two domains with similar folds, and a central beta-sheet domain between these two domains. The molecules contain two lipid-binding sites, one in each domain near the interface of the barrels and the central beta-sheet. 

Of all the novel protein types found in nematodes, only two have had biochemical activites ascribed, and these both happen to be lipid-binding proteins (LBPs). This chapter will focus on these, plus those that are structurally similar to those of vertebrates but appear to have nematode-specific modifications to their structures and functions. 

As-p18, the First Secreted Cytoplasmic Lipid-binding Protein... 

The various types of novel lipid-binding protein from nematodes can... 

Finally, there are the questions that these novel proteins pose. Do any of these unusual lipid-binding proteins, or modifications of otherwise usual proteins, have any role in parasitism Are they secreted to the advantage of the parasite and, if so, in what way ... 

Barrett, J., Saghir, N., Timanova, A., Clarke, K and Brophy, P.M. (1997) Characterisation and properties of an intracellular lipid-binding protein from the tapeworm Moniezia expansa. European Journal of Biochemistry 250, 269-275. 

Janssen, D. and Barrett, J. (1995) A novel lipid-binding protein from the cestode Moniezia expansa. BiochemicalJournal ill, 49—57. 

Kennedy, M.W. (2000b) The polyprotein lipid binding proteins of nematodes. Biochimica et Biophysica Acta 1472,149-164. 

Kennedy, M.W. and Beauchamp, J. (2000) Sticky finger interaction sites on cytosolic lipid binding proteins Cellular and Molecular Life Sciences 57, 1379-1387. 

Kennedy, M.W., Britton, C., Price, N.C., Kelly, S.M. and Cooper, A. (1995c) The DvA-1 polyprotein of the parasitic nematode Dictyocaulus viviparus. a small helix-rich lipid-binding protein. Journal of Biological Chemistry 270, 19277-19281. 

LaLonde, J.M., Levenson, M.A., Roe,J.J., Bemlohr, D.A. and Banaszak, L.J. (1994) Adipocyte lipid-binding protein complexed with arachidonic acid titration calorimetry and X-ray crystallographic studies. Journal of Biological Chemistry 269, 25339-25347. 

Shen, W.-E., Sridhar, K., Bernlohr, D.A. and Kraemer, F.B. (1999) Interaction of rat hormone-sensitive lipase with adipocyte lipid-binding protein. Proceedings of the National Academy of Sciences USA 96, 5528—5532. 

Simpson, MA, LiCata, V.J., Coe, N.R. and Bernlohr, D.A. (1999) Biochemical and biophysical analysis of the intracellular lipid binding proteins of adipocytes. Molecular and Cellular Biochemistry 192, 33—40. 

To demonstrate an application of TIRF-FLIM, a FRET study of annexin A4 translocation and self-aggregation near the plasma membrane is shown in Fig. 9.4. This is a particularly useful application of TIRF-FLIM, since TIRF provides the spatial contrast of detecting only molecules immediately adjacent to the plasma membrane and the lifetime contrast reports on the aggregation state of annexin A4. Annexins are calcium-dependent lipid-binding domains with a different type of lipid binding domain compared to the common C2 domains (e.g., found in protein kinase C). Annex-ins consist of an N-terminal domain and a core domain binding calcium and phospholipids. The core domain is conserved in the... 

Martenson, R. and Uyemura, K. Myelin P2, a neuritogenic member of the family of cytoplasmic lipid binding proteins. In R. E. Martenson (ed.), Myelin biology and chemistry. Boca Raton, FL CRC Press, 1992, pp. 509-530. 

---