A STUDY OF CHEMICAL EFFECTS OF IONIZING RADIATION ON INDIVIDUAL AMINO ACIDS WITHIN THE INTACT AND PURE PROTEIN MOLECULES. PART I. EFFECT ON ATP: CREATINE PHOSPHOTRANSFERASE. PART II. IRRADIATION INDUCED INTERCONVERSION OF AMINO ACIDS AND CONCOMITANT CO$sub 2$ FIXATION. Description of Research and Results for Period March 1, 1962 through February 28, 1963

Technical Report · Wed Oct 30 23:00:00 EST 1963

OSTI ID:4780041

Friedberg, F

The adenosine triphosphate-creatine phosphotransferase activity was assayed in samples of protein and enzyme previously irradiated. Whereas in the intact protein solution histidine is most radiosensitive, methionine was found to be most labile in the corresponding amino acid hydrolysate in solution. Phenylalanine and arginine were also destroyed faster in protein hydrolyzed before radiation exposure. Incorporation into a polypeptide chain altered the radioinduced chemical changes. The decline in enzymatic activity was more rapid than the disappearance of -SH groups. The relation of -SH groups to enzyme activity and radiosensitivity of protein compounds is discussed. Amino acids formed by interconversion as a result of the gamma irradiation of peptide were identified. Data are tabulated. The mechanism involved in the formation of aspartic acid from glutamic acid and concomitant CO/sub 2/ fixation was investigated in poly-L-glutamic acid irradiated in the presence of tion for aspartic acid. Possible reaction mechanisms involved are discussed. (C.H.)

• Research Organization: Howard Univ., Washington, D.C.
• NSA Number: NSA-17-002826
• OSTI ID: 4780041
• Report Number(s): TID-17048
• Country of Publication: United States
• Language: English

Related Subjects

AMINO ACIDS
ARGININE
ASPARTIC ACID
BIOCHEMISTRY
BIOLOGY AND MEDICINE
CARBON DIOXIDE
CHEMICAL REACTIONS
ENZYMES
GAMMA RADIATION
GLUTAMIC ACID
HISTIDINE
HYDROLYSIS
METHIONINE
ORGANIC NITROGEN COMPOUNDS
PHENYLALANINE
PROTEINS
RADIATION EFFECTS
RADIOAUTOGRAPHY
RADIOSENSITIVITY
SODIUM CARBONATES
SOLUTIONS
TRANSFERASES