Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cell transformation is associated with a dramatic collapse of a graphic fingerprint characteristic of normal cells, as measured by phase fluorimetry. This is demonstrated on adenosine deaminase (ADA, EC 3.5.4.4), an established malignancy marker. ADA activity is known to decrease markedly in chick embryo fibroblasts (CEF) transformed by Rous sarcoma virus. The high affinity between the catalytic small subunit ADA (SS-ADA) and its membranal complexing protein (ADCP) (which abounds on the plasma membrane of CEF) allowed the hybridization of fluorescent labeled SS-ADA with native ADCP on CEF. Multifrequency differential phase fluorimetry responded remarkably to the state of this hybrid membrane protein. The transformation process is shown to have led to increased membrane fluidity and rotational mobility of ADCP as well as to its reduced availability to SS-ADA binding. The hypothesis of protein vertical sinking into the lipid core of the membrane is now given support by our spectroscopic data. Additional models are considered. A regulatory role is thus suggested for the complexing protein, which may also account for (a) reduced ADA activity in transformed cells and (b) detachment, exclusive to normal cells, upon addition of SS-ADA in excess.
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PMID:Adenosine deaminase in cell transformation. Biophysical manifestation of membrane dynamics. 284 78

The rate of deamination of 5'-deoxy-5'-S-isobutylthioadenosine [(iBuS5'Ado] in chick embryo fibroblasts was substantially reduced after their infection and morphological transformation by Rous sarcoma virus. Concomitant with the reduction in rate of (iBuS)5'Ado deamination there was a decrease in adenosine deaminase and 5'-adenylic acid deaminase activities. The drop of these activities was related to infection and not to the expression of the src gene. (iBuS)5'Ado was deaminated by at least three enzymes or isoenzymes whose apparent molecular weights have been estimated to be 295000, 121000 and 37000 respectively. Two of these enzymes have been characterized as 5'-adenylic acid deaminase and the heavy form of adenosine deaminase, respectively.
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PMID:Simultaneous decrease in deamination of 5'-adenylic acid and 5'-deoxy-5'-S-isobutylthioadenosine in chick-embryo fibroblasts infected by Rous sarcoma virus. 624 91