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Biomedical subjects

A Grasso

Publications and source records attributed to A Grasso.

At least 145 records · Page 8Linked to original sources
PubMed1976

Preparation and properties of a neurotoxin purified from the venom of black widow spider (Latrodectus mactans tredecimguttatus).

A neurotoxin of the venom of the spider Latrodectus mactans tredecimguttatus, has been prepared in a homogeneous form and examined by a variety of techniques. The protein has a molecular weight of 130 000 and its toxicity in mice is about 49 000 LD50 mg pure protein/g body weight. The toxin releases norepinephrine from synaptosomes prepared from rat brain and shows most of the toxic effects of the crude venom preparation.

Amino Acids↗
PubMed1976

14-3-2 protein in rat primary and transplanted gliomas and neurinomas and in clonal cell lines.

Experimental neurogenic tumors were induced transplacentally in rats by single injections of ethylnitrosourea (ENU). The resulting primary tumors as well as isogenic transplantation tumor lines and clonal cell lines derived therefrom were examined for their content of the brain specific protein 14-3-2 by a quantitative microcomplement fixation assay. The content of S-100 protein in the samples studied is given as well. Some of the tumors of glial or Schwann cell origin did contain 14-3-2 protein ranging from 0.6 to 1.5 mug 14-3-2 per mg total soluble protein. Our experiments also showed that the ability of a tumor to produce this specific protein is transplantable over a series of subcutaneous isogenic transplantations while in the transplantation tumors the content of this protein seemed to be reduced. We were not able so far to find a correlation between the morphology of a tumor and its capability to produce a specific protein. The clonal cell line RN2 of Schwann cell origin which has been previously described in detail contained both the brain specific proteins 14-3-2 and S-100 in comparable amounts ranging from 0.3 to 0.6 and from 0.4 to 1.0 mug specific protein per total soluble protein respectively.

Animals↗
PubMed1969

Variations in sulfhydryl, disulfide, and protein content during synchronous and asynchronous growth of HeLa cells.

The cellular contents of protein-bound and nonprotein sulfhydry (-SH) and disulfide (-SS-) groups were measured in both asynchronous and synchronous HeLa S3 cultures. About 90% of these groups are associated with proteins, the majority in the -SH form. The content of protein-bound groups, and hence the total content of -SH and -SS- groups (28 x 10(-15) moles/cell, or 1.1 x 10(-6) moles/g protein on average), changes in parallel with the protein content (which varies between 2 and 4 x 10(-10) g/cell) as asynchronous populations pass from the lag through the exponential to the stationary phase of growth. The concentration of nonprotein -SH groups, in contrast, increases 10-fold during lag phase and decreases in stationary phase; it follows the protein concentration closely during the exponential phase, at a level of about 2.8 x 10(-15) moles/cell. In synchronous cultures the protein content doubles during the cell cycle, possibly in an exponential fashion. The total -SH and -SS- content also doubles, but the rate of increase appears to fluctuate. The concentrations of the protein-bound groups show 2- to 3-fold fluctuations per unit protein: protein-bound -SH groups and mixed -SS- linkages rise to maxima while protein-bound -SS- groups fall to a minimum at the G(1)/S transition, and fluctuations in these groups occur again during G(2). In addition, the protein-bound -SH concentration falls continuously during the S phase. The nonprotein -SH concentration undergoes the largest (relative) fluctuations, dropping from 4 x 10(-15)moles/cell in early G(1) to about 0.4 x 10(-15) moles/cell (of standard protein content) at the end of G(1), and then rising to 30 times this value by the end of S.

Arginine↗