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Biomedical subjects

C B Wang

Publications and source records attributed to C B Wang.

32 records · Page 2Linked to original sources
PubMed1989

The effect of macrophage-conditioned medium on metabolism of normal very low density lipoprotein by fibroblasts.

Triglyceride was accumulated saturably in cultivated human fibroblasts exposed to increasing concentration of normal very low density lipoprotein (N-VLDL). Characterization of binding and degradation of 125I-N-VLDL by the cells indicated a direct uptake of intact N-VLDL particles via the cell surface receptor. Competition of unlabelled N-VLDL and LDL with 125I-N-VLDL in fibroblasts suggested that LDL receptor may be involved in this process. An unsaturable triglyceride accumulation in fibroblast induced by macrophage-conditioned medium containing N-VLDL was also observed. Intracellular triglyceride content, in this case, is linearly correlated with the concentration of N-VLDL in the medium and results mainly from re-esterification of fatty acid produced by hydrolysis of VLDL-triglyceride by lipoprotein lipase of macrophage.

Boronic Acids↗
PubMed1982

Picosecond photochemistry of a cofacial diporphyrin containing iron(III) and zinc(II): Mimicking electron transfer between cytochrome c and the primary electron donor in reaction centers of photosynthetic bacteria.

Comparison of picosecond kinetic and spectroscopic data for Zn octaethylporphine and Fe(III)Cl octaethylporphine with that for Zn-Fe(III)Cl, a cofacial diporphyrin composed of a Zn porphyrin covalently bound to an Fe(III)Cl porphyrin with two chains of five atoms each, supports the assignment of a light-driven electron transfer (k > 10(11)s(-1)) within Zn-Fe(III)Cl to form [Zn(+).-Fe(II)]Cl. The kinetics (k approximately 10(10)s(-1)) and thermodynamics of the reverse electron transfer are compared to those of a similar electron transfer in bacterial photosynthesis, the reduction of an oxidized bacteriochlorophyll dimer, (BChl)(2) (+)., by Fe(II) cytochrome c.

Journal Article↗
PubMed1981

Electron transport across glycerol monooleate bilayer lipid membranes facilitated by magnesium etiochlorin.

The transport of electrons across biological membranes is believed to play an important role in many biophenomena. Although there have been many examples of systems which may be transporting electrons across Mueller-Rudin bilayer lipid membranes (blm), none has been well characterized. The system we describe here comprises a glycerol monooleate blm containing a magnesium etiochlorin (Mg-C) separating two aqueous phases each containing ferricyanide, ferrocyanide, KCl, and a platinum electrode. The E0s for the Mg-C+/Mg-C and ferri-/ferrocyanide couples are 0.22 and 0.24 V vs. SCE. Thus the MG-C+/Mb-C system is easily poised by the ferri-/ferrocyanide system. When the potentials of the ferri-/ferrocyanide couples are different on each side of the blm we show that the open-circuit membrane potential nearly equals the difference between the redox potentials. This is unequivocal evidence that electrons are being transferred across the blm from one aqueous phase to the other. On the basis of these experiments we deduce that electron transport is the major charge transport mechanism. When redox potentials are the same on each side of the blm, the conductance of the membrane can be greater than 10(-3) S/cm2. The conductance is proportional to the second power of the concentration of Mg-C in the membrane-forming mixture. A number of additional experiments are described which attempt to elucidate the mechanism of electron transfer. We believe that our data are consistent with the idea of an electron-hopping mechanism in which the transmembrane electron transport occurs by a series of second-order electron transfers between membrane-bound electron donors (Mg-C) and acceptors (Mg-C+). Alternative explanations are presented.

Electron Transport↗