Diversity and distribution of CYP gene family in Bactrian camel.

Cytochrome P450 (CYP) enzymes belong to a superfamily of monooxygenases which are phase I enzymes responsible for the first pass metabolism of about 90% of drugs in animals. However, these enzymes are often polymorphic and metabolism of the same drug in different species or different individuals is influenced by genetic and non-genetic factors. Bactrian camels are capable of survival in harsh living environments, being able to consume diets that are often toxic to other mammals and can tolerate extreme water and food deprivation. The aim of this study was to investigate whether the Bactrian camel's special metabolic pathways and unique detoxification capabilities are attributable to particularities of the CYP gene family. The Bactrian camel's whole genome sequencing data were systemically analyzed and annotated, and then, CYP gene family was searched from the whole protein database and compared with CYP gene families of cattle, horse, chicken, and human. The total of 63 CYP gene copies were found in Bactrian camel's whole genome and were classified into 17 families and 38 subfamilies. Among them, 9 multi-gene families were found, and CYP2, CYP3, and CPY4 have 27, 6, and 7 subfamilies, accounting for 43, 10, and 11% in camel CYP gene, respectively. In comparison with cattle, chicken, horse, and human, the distribution of CYP gene subfamilies in camel is different, with more CYP2J and CYP3A copies in the Bactrian camel, which may contribute to the Bactrian camel's specific biological characteristics and metabolic pathways. Comparing to the cow, horse, chicken, and human CYP genes, the distribution of CYP gene subfamilies is distinct in the Bactrian camel. The higher copy number of CYP2J gene and CYP3A gene in Bactrian camel may be the important factors contributing to the distinct biological characteristics and metabolic pathways of Bactrian camels for adaptation to the harsh environments.

Purification and quantification of heavy-chain antibodies from the milk of bactrian camels.

Camel milk has a unique composition with naturally occurring heavy-chain antibodies (HCAbs), which exert rehabilitating potencies in infection and immunity. To characterize HCAb in camel milk, immunoglobulin G (IgG) was isolated from the milk of Camelus bactrianus by a combination of affinity chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis to purify and size-fractionate protein A and protein G, which were further identified by Western blotting, and were quantified by bicinchoninic acid (BCA) and ELISA. The results indicated that IgG1 fraction contains molecules of 50 kDa heavy chains and 36 kDa light chains. The HCAbs (IgG2 and IgG3 fractions) devoid of light chains, contain heavy chains of 45 kDa and 43 kDa, respectively, the amounts of which were significantly higher than that of the IgG1 in the milk of bactrian camels. Above all, we revealed the considerable amounts of HCAbs in the milk of bactrian camels, and developed a novel method for their purification and quantification. These findings provide the basis for developing potential effects of camel milk and its interface with the dairy industry, as well as future investigations of HCAb and its roles in human health and diseases.