Biomaterial Database

Inhibition of delta-aminolevulinic acid dehydratase in human red blood cells by lead and activation by zinc or cysteine. 1979

Y Mauras, and P Allain

Inhibition of blood delta-aminolevulinic acid dehydratase(ALA-D) activity by lead was studied in vivo and in vitro. In vivo, a negative linear correlation (r = -0.85) was found between the logarithmic values of ALA-D activity and blood lead levels. In vitro the inhibitory effect of lead on blood ALA-D activity increased both with contact time and contact temperature of lead with blood before ALA-D assay. Maximum enzyme inhibition occurred after 14 h of contact at 25 degrees C. Inhibition of ALA-D activity by lead, in vivo as well as in vitro, is suppressed by the addition of zinc or cysteine. The logarithmic values of the activity ratios increase linearly with blood lead concentrations. The increase in ALA-D activity brought about by the addition of zinc or cysteine can be used to identify cases of low enzyme activity with no lead intoxication involved. The same technique can also detect cases in which ALA-D inhibition may be concealed by a presumably high initial enzyme activity as observed in some patients.

UI	MeSH Term	Description	Entries
D007854	Lead	A soft, grayish metal with poisonous salts; atomic number 82, atomic weight 207.2, symbol Pb.
D003545	Cysteine	A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.	Cysteine Hydrochloride,Half-Cystine,L-Cysteine,Zinc Cysteinate,Half Cystine,L Cysteine
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D004912	Erythrocytes	Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.	Blood Cells, Red,Blood Corpuscles, Red,Red Blood Cells,Red Blood Corpuscles,Blood Cell, Red,Blood Corpuscle, Red,Erythrocyte,Red Blood Cell,Red Blood Corpuscle
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000623	Porphobilinogen Synthase	An enzyme that catalyzes the formation of porphobilinogen from two molecules of 5-aminolevulinic acid. EC 4.2.1.24.	Aminolevulinate Hydro-Lyase,Aminolevulinic Acid Dehydratase,ALA-Dehydrase,delta-Aminolevulinate Dehydratase,delta-Aminolevulinic Acid Dehydratase,ALA Dehydrase,Acid Dehydratase, Aminolevulinic,Acid Dehydratase, delta-Aminolevulinic,Aminolevulinate Hydro Lyase,Dehydratase, Aminolevulinic Acid,Dehydratase, delta-Aminolevulinate,Dehydratase, delta-Aminolevulinic Acid,Hydro-Lyase, Aminolevulinate,Synthase, Porphobilinogen,delta Aminolevulinate Dehydratase,delta Aminolevulinic Acid Dehydratase
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D015032	Zinc	A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.