Factors affecting the In Vitro inactivation of adolase by x-rays

Conference · Wed Aug 15 04:00:00 EDT 1962

OSTI ID:4875344

Quintiliani, M.; Boccacci, M.

The influence of urea and of various protective compounds on the in vitro inactivation of aldolase by x rays was studied. Low concentrations of urea protect the enzyme from the inactivation, whereas high concentrations, able to induce an unfolding of the protein molecule, increase the degree inactivation by a given dose of radiation. Cysteamine, cystamine, aminoethyl-isothio-uronium, and glutathione, all protect the aldolase in solution from the inactivation by x rays. Cystamine is as protective as cysteamine, in equimolecular concentrations, when high inactivation levels are reached. No protection can be demonstrated when the aldolase, after incubation with the tested compounds, is precipitated and redissolved in a new medium before irradiation. Nevertheless, with S/sup 35/ labeled cystamine, it can be demonstrated that at least seven residues of cysteamine are bound to each aldolase molecule. The protective power of glutathione is reduced by a factor of about 0.2 in the presence of 4 M urea. The possible implications of these findings are discussed. (auth)

• Research Organization: Istituto Superiore di Sanita, Rome (Italy)
• NSA Number: NSA-17-031961
• OSTI ID: 4875344
• Report Number(s): CONF-19--4; AED-Conf--62-217-184
• Country of Publication: Italy
• Language: English

Related Subjects

AET
ALDOLASE
AMINES
AMINO ACIDS
BIOCHEMISTRY
BIOLOGY AND MEDICINE
CONFERENCE
CYSTAMINE
CYSTEAMINE
EFFICIENCY
ENZYMES
ETHYL RADICALS
GLUTATHION
LABELLED COMPOUNDS
MEA
MOLECULES
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PRECIPITATION
PROTEINS
QUANTITY RATIO
RADIATION DOSES
RADIATION EFFECTS
RADIATION PROTECTION
SOLUTIONS
SULFUR 35
UREA
VARIATIONS
X RADIATION