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Biomedical subjects

H Kim

Publications and source records attributed to H Kim.

At least 937 records · Page 52Linked to original sources

Fusion of phospholipid vesicles mediated by cytochrome c.

Fusion of phosphatidylserine/phosphatidylethanolamine (1/1) vesicles induced by cytochrome c is studied at a wide range of pH values. A pH profile for the fusion with maximum values at pH 5 and pH 8 is obtained and this is found to be similar to the profile for cytochrome c binding to the vesicles. The binding property of apocytochrome c to the same phospholipid vesicles is found to be about the same as that of the cytochrome c at low ionic strength, but very different at high salt concentrations. No appreciable fusion of vesicles by apocytochrome c is observed. Proteolytic treatment and dansyl chloride labeling of cytochrome c- and apocytochrome c-vesicle complexes show that the C-terminal segments of these proteins with molecular weights of about 3000 and 5000, respectively, penetrate the bilayer. The hydrophobic labeling studies with photoreactive phosphatidylcholine in the bilayer show that segments of both cytochrome c and apocytochrome c go deep into the bilayer.

Amino Acid Sequence↗

Insulin receptor overexpression in a human pre-B acute lymphocytic leukemia cell line with a t(1;19) chromosome translocation near the INSR locus.

Human pre-B acute lymphocytic leukemia (ALL) cell line 697 contains a disease-specific chromosomal translocation, t(1;19), near the insulin receptor locus (INSR). Insulin binding, insulin receptor kinase and cell surface immunofluorescence experiments all show that 697 cells express more surface insulin receptors than 207 cells, a line of pre-B ALL cells that lack the t(1;19). Northern blot analysis confirms that 697 cells have increased levels of mRNA for the insulin receptor. Gene dosage and in situ hybridization analysis indicate that only two copies of the INSR locus are present in 697 cells, one on the translocation chromosome and one on the normal chromosome 19. The results described here demonstrate that transcriptional up-regulation of the INSR locus is correlated with the t(1;19) translocation found in human pre-B ALL cell line 697.

Blotting, Northern↗