An-Najah Staff

A breakthrough in immunity has occurred by the discovery of a new type of antibodies which are  devoid of the light chains in family Camelidae. They were found in Camelus dromedarius serum as they comprise approximately 50% of total serum antibodies (Hamers-Casterman et al., 1993). They also were found in milk, their high stability allows them to participate in natural preservation of camel milk in deserts with out using refrigerators (El-Hatmi et al., 2007). In contrast to conventional antibodies, camel heavy chain antibodies and their derived nanobodies showed great stability under different conditions.Dumoulin et al. (2002) studied the effect of different denaturing agents including guanidinium chloride, urea, temperature and pressure on the conformational stability of nanobodies. Omidfar et al. (2007) tested the thermal stability of Camelus bactrianus nanobodies, heavy chain and conventional antibodies. They found that IgG  lost approximately 40% of its functionality after 50 hours incubation at 37°C, whereas IgG and IgG  retained 88% of its functionality after 100 hours incubation at 37°C. Here In our study; camel IgG 3 antibodies showed high resistance to extreme pH values as they retained 90% of their binding activity after 2 h incubation at pH 2. They also showed significant resistance to thermal denaturation at high temperatures (>70 3  ○ C). Interestingly, these IgG  antibodies conserved 60% of their binding activity after one week incubation at room temperature and 55% after 21 days.