%0 Journal Article
%T Interaction of Normal and Sickle Hemoglobins for Sodium Dodecylsulphate and Hydrogen Peroxide at pH 5.0 and 7.2
%A Fortunatus C. Ezebuo
%A Sabinus Oscar O. Eze
%A Colin B. Lukong
%A Ferdinand C. Chilaka
%J ISRN Hematology
%D 2013
%R 10.1155/2013/629640
%X Clinical manifestations of malaria primarily result from proliferation of the parasite within the hosts¡¯ erythrocytes. The malaria parasite digests hemoglobin within its digestive vacuole through a sequential metabolic process involving multiple proteases. The activities of these proteases could lead to the production of ROS which could lead to the death of the parasites due to the destruction of their membrane. The action of SDS on hemoglobins can be likened to the way malarial proteases destabilizes host hemoglobin. Hence, the study was designed to determine the binding parameters of SDS and H2O2 for normal, sickle trait carrier and sickle hemoglobins at pH 5.0 and 7.2 using UV-VIS Titration Spectrophotometry. Hb-SDS interactions were significantly different at pH 5.0 but were not at pH 7.2. Also, Hb-H2O2 interactions were statistically different at pH 5.0 and 7.2. The interactions suggest that HbA and HbS are easily destabilized than HbAS and that HbAS has more affinity for H2O2. These suggest a production of more ferryl intermediates or hydroxyl radicals. All these interactions may hinder the development of the malaria parasite at the intraerythrocytic stage and could likely account for a significant proportion of the mechanism that favours the resistance to malaria by individuals with HbAS. 1. Introduction Malaria is one of the most important infectious disease problems of humans, particularly in developing countries. Plasmodium falciparum, the most virulent human malaria parasite, is responsible for hundreds of millions of illnesses and more than one million deaths each year [1]. Clinical manifestations of malaria primarily result from proliferation of the parasite within the hosts¡¯ erythrocytes. During this process, hemoglobin is utilized as the predominant source of nutrition. This is because during the intraerythrocytic development and proliferation, the parasites ingest more than 75% of the hosts¡¯ hemoglobin and digest them within the digestive vacuole¡ªan acidic organelles with estimated pH of 5.0¨C5.4¡ªthrough a sequential metabolic process involving multiple proteases [2, 3], and action of sodium dodecylsulphate (SDS) on hemoglobins can be likened to the way proteases secreted by malaria parasites destabilizes host hemoglobin for their homeostasis. Hydrogen peroxide is a major reactive oxygen species in living organisms and can produce reactive hydroxyl radicals or ferryl intermediate [Fe(IV)=O]2+ by Fenton or Fenton like reaction [4]. Hanspal et al. [5] reported that Plasmodium falciparum-derived cysteine protease, falcipain-2, cleaves host
%U http://www.hindawi.com/journals/isrn.hematology/2013/629640/