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Human plasma gelsolin was specifically eluted from a Cibacron Blue F3GA column with 1 mM adenosine, guanosine, cytidine and uridine di- and triphosphates, except for cytidine 5'-diphosphate. Inorganic polyphosphates also eluted gelsolin, but neither nicotinamide adenine dinucleotide nor nicotinamide adenine dinucleotide phosphate did so. The results suggest that a terminal pyrophosphate structure might be essential for the specific elution. After elution with 1 mM adenosine 5'-triphosphate, additional gelsolin was eluted by washing the column with a high salt concentration. This indicates that human plasma gelsolin may bind to Cibacron Blue F3GA in at least two different ways.

A method for enzymatic assay of imidazole acetic acid (ImAA) was developed, based on the strict substrate specificity of imidazole acetate monooxygenase from Pseudomonas sp. [Maki et al. (1969) J. Biol. Chem., 244., 2942-2950], which catalyzes concomitant conversion of NADH to NAD+. Thus, ImAA was determined by measuring decrease in absorbancy at 340 nm. Tissue extracts were partially purified and/or concentrated by column chromatography on Bio-Rad AG-1 before enzymatic assay. The lowest measurable level of ImAA by this method was 2 nmol.

A human hepatoma cell line, HuH-7, which was established from a hepatoma tissue removed at surgical operation from an adult Japanese male, grows autonomously in a serum-free chemically defined medium. A human hepatoma-derived growth factor with potent growth-promoting activity, was partially purified from the conditioned medium of HuH-7 cells, using ion-exchange, heparin affinity chromatography and gel filtration. The partially purified growth factor (HuHGF) is acid- and heat-labile, and sensitive to reduction and trypsin digestion. HuHGF, which is of relatively high molecular weight (about 64 kDa) examined by gel filtration, stimulates not only the DNA synthesis of Swiss mouse 3T3 fibroblasts, but also the growth of HuH-7 cells in serum-free chemically defined medium, suggesting that it is produced by and acts on HuH-7 cells as an autocrine growth factor. This putative growth factor may play an important role in the autonomous growth of hepatoma and may lead to useful diagnostic or therapeutic approaches to human hepatoma.