Purine-metabolizing enzymes of Tetrahymena pyriformis.
نویسنده
چکیده
Except for the recent report of Friedkin on pyrimidine nucleoside phosphorylase (2) and several papers from this laboratory dealing with ribonuclease and deoxyribonuclease (3, 4), little information is available concerning the occurrence of nucleolytic and nucleosynthetic enzymes in the ciliated protozoan, Tetrahymena pyrif0rmis.l This is in contrast to a number of studies carried out on the purine and pyrimidine growth requirements of the organism in synthetic media with labeled and non-labeled substrates. Thus, it has been shown that Tetrahymena requires an exogenous source of guanine (5) (guanosine, guanylic acid), and that xanthine (5) and xanthosine (6) are nutritionally inert. While such growth experiments constitute an important approach to the metabolism of nucleic acid intermediates, strong supporting evidence for the occurrence of various purine interconversions may be obtained by the demonstration of specific enzymes in extracts of the organisms. The purpose of the present study is to survey cell-free preparations obtained from T. pyriformis for the presence of several purine-metabolizing enzymes known to occur in vertebrates, invertebrates, and microorganisms, and to determine some of the properties of these enzymes.
منابع مشابه
Studies of Membrane Formation in Tetrahymena Pyriformis
A method has been devised to fractionate cells of Tetrahymena pyriformis, yielding pure or highly enriched preparations of cilia, cilia-associated soluble material, pellicles, mitochondria, microsomes, and postmicrosomal supernatant. The method prevents the destructive action of lipolytic enzymes commonly associated with this organism. Analysis of the membrane lipids of these fractions reveals ...
متن کاملSTUDIES OF MEMBRANE FORMATION IN TETRAHYMENA PYRIFORMIS II . Isolation and Lipid Analysis of Cell Fractions
A method has been devised to fractionate cells of Tetrahymena pyriformis, yielding pure or highly enriched preparations of cilia, cilia-associated soluble material, pellicles, mitochondria, microsomes, and postmicrosomal supernatant . The method prevents the destructive action of lipolytic enzymes commonly associated with this organism . Analysis of the membrane lipids of these fractions reveal...
متن کاملA NEW BIOLOGICAL SCREENING SYSTEM FOR LOCAL ANAESTHETICS BY INHIBITION MOBILITY OF TETRAHYMENA PYRIFORMIS
An alternative in vitro approach to drug screening has been the use of human cell cultures for antiviral agents and microbial cell cultures for the assessment of the carcinogenic potential of selected compounds. A number of protozoan species have been also used as drug screens for anti-protozoal agents. The ciliated protozoan Tetrahymena pyriformis species has been widely utilised as a dru...
متن کاملExocytotic and phagocytotic activities of Tetrahymena pyriformis are not influenced by Clostridium botulinum neurotoxins
The ciliate Tetrahymena pyriformis GL was tested for its applicability to the detection of botulinum neurotoxins. Botulinum neurotoxins attack different proteins of the SNARE-complex, which is involved in fusion processes of the cellular membrane traffic. The exocytosis of enzymes and the phagocytosis of germs include several presumptive SNARE-dependent pathways within T. pyriformis. Acid phosp...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of biological chemistry
دوره 220 1 شماره
صفحات -
تاریخ انتشار 1956