The phagokinetic tracks of 3T3 cells.

This paper describes a technique of visualizing tracks of cultured cells moving on a glass substrate covered with gold particles. It leads to the following observations: -If the tracks of many cells are examined, cell line characteristic track patterns become apparent. -In several cases, second or third generation descendents of 3T3 cells were observed to repeat track patterns of their ancestor cell. -If a 3T3 cell collides with another 3T3 cell or a nonmigrating BSC-1 cell, it forms an outgoing track from the impact area as if the cell was elastically reflected at the target.     

The 3H-labelling of bilirubin.

A simple method has been developed for the preparation of 3H-labelled bilirubin IX-alpha from bilirubin dimethyl ester. The label is located in the propionic acid side chains, and there is no isomerization of the bilirubin during the preparation.     

The heparan sulfates of Swiss mouse 3T3 cells. The effect of transformation.

Three major pools of heparan sulfate have been isolated from cultures of Swiss mouse 3T3 and SV40-transformed 3T3 cells: cell-surface, medium, and intracellular heparan sulfates. The cell-surface heparan sulfate is a high molecular weight proteoglycan which is partially degraded by pronase. Before pronase treatment, it has a peak molecular weight (as estimated by gel filtration) of approx. 7.2 . 10(5) in contrast to only 2.4 . 10(5) after pronase treatment. The medium heparan sulfate appears to be similar in structure to the cell-surface heparan sulfate, since they coelute on Bio-Gel A-15m and DEAE-cellulose, and are both proteoglycans. In contrast, the intracellular heparan sulfate has a low molecular weight (6.0 . 10(3)) and has little if any attached protein. Both the medium and intracellular heparan sulfate exhibit the transformation-associated change in structure reported earlier for cell-surface heparan sulfate (Underhill, C.B. and Keller, J.M. )1975) Biochem. Biophys. Res. Commun. 63, 448--454). This transformation-associated change, detected by DEAE-cellulose chromatography is not the result of changes in either molecular weight or protein core. Cellulose acetate electrophoresis of the cell-surface heparan sulfate at pH 1 suggests that the transformation-associated change in structure is due to a difference in sulfate content. Both types of heparan sulfate are produced in mixed cultures of 3T3 and SV3T3 cells, indicating that neither serum factors in the culture medium nor secreted cell products are responsible for the transformation-associated change in heparan sulfate structure. The presented data are discussed with respect to the postulated role of heparan sulfate in cell social behavior.     

The structure of hikizimycin. I. Identification of 3-amino-3-deoxy-D-glucose and cytosine as structural components

The molecular formula for hikizimycin, a new antibiotic isolated from Streptomyces A-5, is now established as C₂₁H₃₇N₅O₁₄. Evidence in support of the occurrence of 3-amino-3-deoxy-D-glucose and cytosine residues in the antibiotic molecules is presented. Methanolysis of N,N′-diacetylhikizimycin gave mainly two components. Fragment A was characterized as methyl 3-amino-3-deoxy-D-glucopyranoside by its conversion into the known methyl 3-acetamido-2,4,6-tri-O-acetyl-3-deoxy-α-D-glucopyranoside. Fragment B, on catalytic hydrogenation followed by acid hydrolysis, gave tetrahydropyrimidin-2-one, characterized as its picrate, thus establishing the presence of a cytosine residue in hikizimycin.     

The arsonomethyl analogue of 3-phosphoglycerate.

4-Arsono-2-hydroxybutanoic acid, the analogue of 3-phosphoglycerate in which -CH2-AsO3H2 replaces -O-PO3H2, was synthesized. It proved to be a substrate for phosphoglycerate kinase. Its Michaelis constant was only slightly higher than that of the natural substrate, but its catalytic constant was about 1300 times smaller.     

The chemistry of polyhalozirconates. Part 3. The preparation of phosphonium hexachlorozirconates

The preparation of various phosphonium hexachlorozirconates from zirconium tetrachloride and zirconium oxide chloride octahydrate is described. In one case a product [(C₆H₅)₃PH]₂ZrCl₆ was found to be unusually resistant to hydrolysis.