Alpha S1-casein polymorphisms in camel (Camelus dromedarius) and descriptions of biological active peptides and allergenic epitopes
Alpha S1-casein polymorphisms in camel (Camelus dromedarius) and descriptions of biological active peptides and allergenic epitopes
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DOI：
10.1007/s11250-016-0997-6
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发表时间：
2016-06-01
影响因子：
1.7
通讯作者：
Pauciullo, Alfredo
中科院分区：
文献类型：
--
作者：
Erhardt, Georg;Shuiep, El Tahir Salih;Pauciullo, Alfredo
采用等电聚焦法对来自苏丹不同地区的193头骆驼（Camelus dromedarius）的牛奶样品进行了酪蛋白变异性的筛选。κ-酪蛋白和β-酪蛋白是单态的，而三种蛋白质模式命名为α（s1）-酪蛋白A，C和D被确定。主要等位基因A在不同生态型中的频率分别为0.79（Lahaoi）、0.75（Shanbali）、0.90（ArabiKhali）和0.88（ArabiGharbawi）。与CSN 1 S1 *A和D相比，CSN 1 S1 *C在外显子5中显示单个G > T核苷酸取代，导致非同义氨基酸交换（p.Glu30 > Asp 30）。在cDNA水平上，在CSN 1 S1 * A、C和D中没有进一步的单核苷酸多态性，而变体CSN 1 S1 *A和CSN 1 S1 *C的特征在于与已经描述的CSN 1 S1 *B相比缺失外显子18，这是由于在内含子17处插入11 bp的DNA改变了前mRNA剪接体机制。建立了聚合酶链-限制性片段长度多态性（PCR-RFLP）方法，在基因组DNA水平上对G > T核苷酸替换进行分型。在计算机上分析了消化后α（s1）-酪蛋白A、C和D之间IgE结合表位和生物活性肽的存在和差异。氨基酸的取代和缺失影响所产生的肽模式，从而修改IgE结合表位和生物活性肽的变体之间被发现，这些不同的肽的过敏性的潜力将通过微阵列免疫测定研究使用血清从牛奶致敏的个人，因为它已经证明了牛α（s1）-酪蛋白变体。
Milk samples of 193 camels (Camelus dromedarius) from different regions of Sudan were screened for casein variability by isoelectric focusing. Kappa-casein and beta-casein were monomorphic, whereas three protein patterns named alpha(s1)-casein A, C, and D were identified. The major allele A revealed frequencies of 0.79 (Lahaoi), 0.75 (Shanbali), 0.90 (Arabi Khali), and 0.88 (Arabi Gharbawi) in the different ecotypes. CSN1S1*C shows a single G > T nucleotide substitution in the exon 5, leading to a non-synonymous amino acid exchange (p.Glu30 > Asp30) in comparison to CSN1S1*A and D. At cDNA level, no further single nucleotide polymorphisms could be identified in CSN1S1* A, C, and D, whereas the variants CSN1S1*A and CSN1S1*C are characterized by missing of exon 18 compared to the already described CSN1S1*B, as consequence of DNA insertion of 11 bp at intron 17 which alter the pre-mRNA spliceosome machinery. A polymerase chain-restriction fragment length polymorphism method (PCR-RFLP) was established to type for G > T nucleotide substitution at genomic DNA level. The occurrence and differences of IgE-binding epitopes and bioactive peptides between alpha(s1)-casein A, C, and D after digestion were analyzed in silico. The amino acid substitutions and deletion affected the arising peptide pattern and thus modifications between IgE-binding epitopes and bioactive peptides of the variants were found. The allergenic potential of these different peptides will be investigated by microarray immunoassay using sera from milk-sensitized individuals, as it was already demonstrated for bovine alpha(s1)-casein variants.