ABSTRACT
Haptoglobin is a plasma protein with hemoglobin binding capacity. Haptoglobin has important biological functions such as binding to free hemoglobin and removes it from the circulation, thus preventing iron loss and kidney damage during intravascular hemolysis, superior antioxidant capacity, protection against free radicals. Studies on the distribution of Hp show that the gene frequencies of Hp dependent on geographical and genetic family. In the other, several authors have showed the correlation between HP types and different diseases, such as inflammation, infection, cardiovascular diseases and malignant tumors. Smoking, hypertention, diabetes mellitus and serum lipid concentrations are risk factors for developing cardiovascular diseases. In addition, Hp polymorphism has been proposed as a risk factor for developing atherosclerotic vasculare disease. In this study, the association between Haptoglobin genotypic distribution and the incidence of coronary heart disease investigated. 50 Iranian patients with coronary heart disease were randomly selected. Genomic DNA extracted from peripheral blood leukocytes. In PCRs with primers A and B, amplification products of 1757 and 3481 bp were amplified from genomic DNA containing alleles Hp[1] and Hp[2], respectively. In the population studied, the distribution of haptoglobin polymorphism was 36% [n = 18] for the Hp[1] - 1 type, 62% [n =31] for the HP[1] - 2 type, and 2% [n = 1] for the HP[2] - 2 type. The trend in this study showing a lower frequency of 3-vessel disease and less severe coronary artery stenosis in patients with the HP[1] - 1 phenotype than in patients with the HP[1] - 2 phenotypes may be indicative of a protective effect of the HP[1] - 1 phenotype against the development of atherosclerotic coronary artery disease
ABSTRACT
Adenosine Deaminase is an amino hydrolase [EC 3.5.4.4] which participates in the purine metabolism where it degrades either adenosine or 2'-deoxyadenosine producing inosine or 2'- deoxy inosine, respectively. The enzyme contains a parallel alpha/beta -barrel motif with eight central beta strands and eight peripheral alpha helices. ADA is located both in the cytosol and on the cell membrane. Since spermine, a natural metabolite, exists in all cells and tissues and its effect on the cell proliferation and enzyme regulation have been reported, thermal inactivation of the ADA and spermine regulatory effect on the ADA activity have been investigated in this study. Percentage of ADA activity in the presence and absence of spermine [1000 microM] in Tris buffer 50 mM, pH 7.5 at physiologic and pathologic temperatures have been reported in the present study. Thermal inactivation curves for ADA in the absence and presence of spermine [1000 microM] in different temperatures ranging from 55 degreeC to 70 degreeC have been drawn. Our data showed that spermine activates the enzyme in the low concentrations of adenosine at 37 degreeC. However, it inhibits ADA activity at 42 degreeC in the same concentrations of substrate. It is concluded that spermine regulatory effect depends on combined influence of temperature and adenosine concentration. Furthermore, thermal stability of the enzyme also depends on temperature in presence of spermine. Binding site of spermine on the enzyme has been identified by docking analysis