Montamas Suntravat and Issarang Nuchprayoon
Background: Russell’s viper venom-factor X activator (RVV-X) is a major procoagulant in Russell’s viper venom, and is composed of a heavy chain (RVV-XH) and two light chains (RVV-XL). It directly activates factor X in the final common coagulation pathway, which leads to rapid formation of blood clots.
Objective: Produce rabbit anti-recombinant protein antibodies and identify their cross-reactivity with two viperine snake venoms.
Methods: cDNA clones encoding RVV-XH and one of the light chains (RVV-XL; LC1) were recombinantly expressed in E. coli BL21 and used as antigens for rabbit immunization. The cross-reactivity of these anti-recombinant protein antibodies with two viperine snake venoms was determined using Western blot analysis.
Results: rRVV-XH was more immunogenic than rRVV-XL. Rabbit anti-rRVV-XH and rRVV-XL IgG antibodies bind specifically to RVV-X, but they do not neutralize purified RVV-X. In addition, rabbit anti-rRVV-XH IgG antibody also bind to an 18-kDa protein in C. rhodostoma venom, and many proteins in C. albolabris venom. Rabbit antirRVV- XL IgG antibody recognized protein bands of crude venoms of C. rhodostoma and C. albolabris at about 25-kDa and 23-kDa, respectively.
Conclusion: Rabbit anti-rRVV-XH and rRVV-XL IgG antibodies cross-reacted with molecules in other viperine venoms, which could have molecules with similar antigenic determinants. These antibodies could be useful to purify snake venom molecules by affinity chromatography as the first step in purification of factor X activator and other cross reacting molecules.
Chalisa Louicharoen Cheepsunthorn and Issarang Nuchprayoon
Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an enzymopathy with high frequency in Southeast Asians. Phuan is a minority tribe in Thailand. The prevalence of G6PD deficiency and its molecular heterogeneity in this population is yet unknown.
Objectives: To characterize molecular heterogeneity of G6PD in Phuan people and investigate whether the heterogeneity of G6PD could be used to delineate the origin of Phuan people in Thailand.
Methods: Cord blood samples from 202 Phuan neonates were tested for G6PD deficiency using a G6PD activity assay. G6PD mutations were determined in G6PD deficient blood samples by polymerase chain reaction-restriction fragment length polymorphism analysis and sequencing.
Results: G6PD deficiency was found in 12 (12.2%) of 98 males and 8 (7.7%) of 104 females in the study population. Molecular analysis was performed on 12 males and 8 females to identify G6PD mutations. G6PD Viangchan (871G→A, 1311C→T)(25.0%) was the most dominant mutation followed by the G6PD Canton (1376G→T) (15.0%), G6PD Union (1360C→T) (10.0%), one case each of G6PD Kaiping (1388G→A) and G6PD Mediterranean (563C→T, 1311C) (5%), and eight G6PD deficient unidentified mutations.
Conclusions: G6PD deficiency in Phuan is highly frequent and G6PD Viangchan(871G→A, 1311C→T) is the most common mutation. Our study suggests that Phuans have coevolved with Thais, and were influenced by gene flow from Chinese and Indian mutations.