Ruffling

My subsequent interest in gas turbines has come mainly from a happy consulting arrangement with Rolls Royce, pic and the many excellent engineers I have worked with there, including particularly Messrs.Wilde, Scrivener, Miller, Hill and Ruffles. The Company remains at the forefront of gas turbine engineering. 

FIGURE 10.17 Proton pumps cluster on the ruffled border of osteoclast cells and function to pump protons into the space between the cell membrane and the bone surface. High proton concentration in this space dissolves the mineral matrix of the bone. 

C1C-6 is a late endosomal chloride transporter. Its disruption in mice led to lysosomal storage disease. C1C-7 is expressed in late endosomes and lysosomes. It needs Ostml as (3-subunit [3]. The disruption of either C1C-7 or Ostml in mice and man leads to severe osteopetrosis, retinal degeneration, and a severe lysosomal storage disease. ClC-7/Ostml is highly expressed in osteoclasts. In these cells, it is inserted together with the proton pump into the specialized plasma membrane ( ruffled border ) that faces the reabsorption lacuna. Osteoclasts are still present in C1C-7 knockout... 

Proteins that cross-link actin filaments bind to their sides to produce bundles or three-dimensional networks (Otto, 1994). In microvilli, approximately 20 actin filaments of the core are cross-linked by villin (95 kD) and fimbrin (68 kD) in helical array to form a compact bundle (Figure 5). Filamin (2 x 250 kD) induces the formation of an actin network with gel formation. By immunofluorescence microscopy, this ABP is found in the ruffled, motile edge of cultured cells, where only actin filaments are abundant. 

Franck, Z., Footer, M., Bretscher, A. (1990). Microinjection of villin in cultured cells induces rapid and long-lasting changes in cell morphology but does not inhibit cytokinesis, cell motility or membrane ruffling. J. Cell Biol. Ill, 2475-2485. 

Ridley, A.J., Paterson, H.F., Johnston, C.L., Diekermann, D., Hall, A. (1992). The small GTP-binding protein rac regulates growth factor-induced membrane ruffling. Cell, 70,401-410. 

Osteoclasts are multinucleated cells derived from pluripotent hematopoietic stem cells. Osteoclasts possess an apical membrane domain, exhibiting a ruffled border that plays a key role in bone resorption (Figure 48-12). A proton-translocating ATPase expels protons across the ruffled border into the resorption area, which is the microenvironment of low pH shown in the figure. This lowers the local pH to 4.0 or less, thus increasing the solubility of hydroxyapatite and allowing demineralization to occur. Lysosomal acid proteases are released that digest the now accessible matrix proteins. 

Fig. 25. The effect of metal ion size on porphyrin ruffling. Very small metal ions [P(V) with an ideal P-N bond length of 1.84 A and low-spin Ni(II) with an ideal Ni-N length of 1.90 A in (a) and (b)) cause extensive S4 ruffling. Metal ions close to the right size (M-N = 2.035 A) give planar structures [Zn(II) in (c)]. Metal ions that are too large [Pb(II) at (d) with ideal Pb-N of 2.39 A] are extruded from the plane of the porphyrin and cause it to dome. For clarity, substituents on the porphyrins such as phenyl or ethyl groups have been omitted. Modified after Ref. (77).

Figure 3 The effect of an Src (-/-) knockout in mice as shown by differences in function and appearance of wild-type and Src-minus osteoclasts. The Src-minus osteoclasts lack the ruffled borders of a normal, resorbing osteoclast, but are viable and can adhere to bone. (From Ref. 8.)...

As you may have gathered by now, I rather enjoy telling tales and ruffling feathers. I also enjoy rocking boats, especially when they are in need of sinking. I hope you have enjoyed the ride. 

The consequences of polychlorination of porphyrins on redox properties of complexes has been investigated.1404 The highly chlorinated porphyrin 3-octachloro-/ /c.vo-tetrakis(3,5-dichloro-2,6-dimethoxyphenyl)porphyrin exhibits a substantial anodic shift for reduction of over 0.5 V and a smaller shift for oxidation versus the unchlorinated precursor. Contrastingly, small potential shifts for the octabromo-substituted 5,10,15,20-tetraphenylporphyrinate arise from the dominance of macrocycle ruffling over electronic effects. In the polychloro complex, distortion does not compensate fully for electron-withdrawing effects of the Cl substituents. 

The complex with the reduced porphyrin derivative 5,10,15,20-tetramethylisobacteriochlorin, [Ni(TMiBC)] (688), has an -ruffled conformation and a bond length pattern indicative of a reduction of aromaticity, both of which are more pronounced than those found for the corresponding porphyrin and chlorin complexes.1786... 

The functionalization of zinc porphyrin complexes has been studied with respect to the variation in properties. The structure and photophysics of octafluorotetraphenylporphyrin zinc complexes were studied.762 Octabromoporphyrin zinc complexes have been synthesized and the effects on the 11 NMR and redox potential of 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraarylporphyrin were observed.763 The chiral nonplanar porphyrin zinc 3,7,8,12,13,17,18-heptabromo-2-(2-methoxyphenyl)-5,10,15,20-tetraphenylporphyrin was synthesized and characterized.764 X-ray structures for cation radical zinc 5,10,15,20-tetra(2,6-dichlorophenyl)porphyrin and the iodinated product that results from reaction with iodine and silver(I) have been reported.765 Molecular mechanics calculations, X-ray structures, and resonance Raman spectroscopy compared the distortion due to zinc and other metal incorporation into meso dialkyl-substituted porphyrins. Zinc disfavors ruffling over doming with the total amount of nonplanar distortion reduced relative to smaller metals.766 Resonance Raman spectroscopy has also been used to study the lowest-energy triplet state of zinc tetraphenylporphyrin.767... 

In Fig. 9.4, the results are shown of an experiment using a double (annexinA4-EYFP+ annexinA4-mCherry) transfected cell immediately after addition of the calcium ionophore ionomycin (top) and 5 min after application of ionomycin (bottom). Clearly visible is the diffuse localization of annexin A4 before relocation and the more structured localization (into membrane ruffles and filopodia) after relocation. More importantly, the EYFP fluorescence lifetime is quenched from 2.9 ns before translocation to... 

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