Down syndrome children with acute megakaryocytic leukemia (AMkL) have higher cure rates than non-Down syndrome acute myeloid leukemia (AML) patients treated with cytosine arabinoside (ara-C). Megakaryoblasts from Down syndrome AML patients are more sensitive in vitro to ara-C than cells from non-Down syndrome AML patients. Somatic mutations in the GATA1 transcription factor have been detected e...

The APOBEC3 proteins form a multigene family of cytidine deaminases with inhibitory activity against viruses and retrotransposons. In contrast to APOBEC3G (A3G), APOBEC3A (A3A) has no effect on lentiviruses but dramatically inhibits replication of the parvovirus adeno-associated virus (AAV). To study the contribution of deaminase activity to the antiviral activity of A3A, we performed a compreh...

An improved method was devised for the estimation of serum adenosine deaminase activity. The principle of the method consists in measurement of a liberated ammonia by the action of the deaminase with a direct colorimetric determination of ammonia concentration [Okuda et al.]. The technique is relatively easy to estimate the serum enzyme activity and can be applied for routine clinical use. The ...

In 1928, Schmidt (1) first described the presence of 5’-adenylic acid deaminase in muscle. He succeeded in separating this enzyme from adenosine deaminase and in isolating inosinic acid and ammonia as products of the reaction. He also reported that it specifically deaminated 5’-adenylic acid. In 1947, Kalckar (2) described two methods for the preparation of this enzyme and introduced a spectrop...

The level of nucleoside deaminase was determined in extracts of mouse tissues obtained during a period of accelerated erythropoiesis induced by hypoxia, hemorrhage, or the injection of phenylhydrazine. Under these conditions a striking (10- to 100-fold) elevation of the enzyme activity occurred in the spleen. Similar results were obtained with the injection of purified erythropoietin. In contro...

Marrow cells induced toward erythroid differentiation by treatment with erythropoietin respond by increasing the rates of iron uptake and hemoglobin synthesis. Study of the enzymes of heme biosynthesis during erythroid differentiation suggests that induction of heme synthesis in these cells is regulated by synthesis of porphobilinogen deaminase. The activities of delta-aminolevulinic acid synth...

The enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase promotes plant growth by sequestering and cleaving plant-produced ACC thereby lowering the level of ethylene in the plant. Decreased ethylene levels allow the plant to be more resistant to a wide variety of environmental stresses. Here the biochemical reaction mechanisms involved in ACC deaminase activity are critically reviewed.

PCR was used to rapidly identify and isolate 1-aminocyclopropane-1-carboxylate (ACC) deaminase genes from bacteria. The Shimodaira-Hasegawa test was used to assess whether phylogenetically anomalous gene placements suggestive of horizontal gene transfer (HGT) were significantly favored over vertical transmission. The best maximum likelihood (ML) ACC deaminase tree was significantly more likely ...

The nature of the association of adenosine deaminase deficiency and severe combined immunodeficiency disease is reviewed . The basis for the molecular heterogeneity exhibited by adenosine deaminase in human tissue and the mechanisms whereby a deficiency of this activity results in the extreme perturbation of the immune system as observed in severe combined immunodeficiency are critically discus...