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C Ceccarini

Publications and source records attributed to C Ceccarini.

67 records · Page 4Linked to original sources
PubMed1966

Trehalase from Dictyostelium discoideum: purification and properties.

The hydrolytic enzyme, trehalase, was isolated and purified approximately 90-fold from the cellular slime mold Dictyostelium discoideum. The purified trehalase has an optimal temperature of 45 degrees C and shows maximum activity at pH 5.5 in citrate buffer. Its Michaelis constant is 1.2x 10(-3)M.

Chemical Phenomena↗
PubMedDate not supplied

Effect of pH on plating efficiency, serum reguirement, and incorporation of radioactive precursors into human cells.

The plating efficiencies of two cell lines (HeLa-AT and WI26 Va) and one cell strain (KL2) appeared to be optimal at pH 7.6 At the optimal pH, ,sing organic buffers, the serum concentration could be reduced by one-half without affecting the initial growth rate or the final population density of the human skin fibroblast strain, KL2. It is suggested that an optimal pH lowers the serum requirement of the cells. The incorporation of [3-H]thymidine, [3-H]uridine, [-3H]fucose and [-14C]amino acids into KL2 was maximal at the pH which normally permits optimal growth of this cell strain. Protein turnover, as measured by loss to the medium of amino acids from prelabeled cells, was pH-independent. Thymidine incorporation did not correlate with culture growth in the cell strain, MS2A.

Blood↗
PubMedDate not supplied

Monoclonal antibodies recognizing a recombinant portion of human alpha-fetoprotein with antigenic selectivity versus albumin.

Determination of serum alpha-fetoprotein is useful in the clinical management of liver cancer, but it has not been particularly helpful in the early diagnosis of this disease, since also non-neoplastic liver diseases may result in small increases of its serum concentration. To improve the clinical performance of this assay, we have previously developed an in vitro culture system, in which the expression of alpha-fetoprotein and albumin could be coordinately modulated by thyroid hormone. This system allowed large scale production and purification of native alpha-fetoprotein to be used as reference material. In addition, we synthesized and cloned in a bacterial expression vector a DNA sequence coding of human alpha-fetoprotein amino acid sequence 38-119. This alpha-fetoprotein sequence was chosen since it is the least homologous to albumin, being the amino acid sequence of the two proteins extremely similar with an overall identity of about 38%. Now we have obtained three hybridomas recognizing with high affinity and specificity both the recombinant fragment and native alpha-fetoprotein. These antibodies, which therefore recognize the native protein in the amino acid sequence 38-119, should allow the development of an immunoassay for alpha-fetoprotein with absolute selectivity versus albumin. This might result in more sensitive clinical determinations, avoiding the possibility of cross-reactions.

Albumins↗