抗體，也叫免疫球蛋白（Ig），是一種能特異性結合抗原的糖蛋白，而抗原是在易感染動物體內引發抗體產生的物質。在體內，抗體是由于外源性分子的侵襲而產生的。抗體以一個或者多個Y字形單體存在，每個Y字形單體由4條多肽鏈組成，包含兩條相同的重鏈和兩條相同的輕鏈。輕鏈和重鏈是根據它們的分子量大小來命名的。Y字形結構的頂端是可變區，為抗原結合部位。任何一個抗體的輕鏈都可以分為κ或λ型（基于小分子多肽結構上的差異），每一個抗體的重鏈則決定了它的類或型。
caution:The sequence shown here is derived from an Ensembl automatic analysis pipeline and should be considered as preliminary data.,developmental stage:Isoform 2 is expressed at lower levels in fetal brain and kidney than in adult brain and kidney.,similarity:Belongs to the TPD52 family.,subunit:Forms homodimer or heterodimer with other members of the family.,tissue specificity:Isoform 2 is expressed in colon, breast, prostate, pancreas and kidney tumor cell lines. Isoform 2 is expressed at high levels in kidney, prostate, brain, small intestine and pancreas, at moderate levels in placenta and colon, at low levels in lung, liver and heart, and at very low levels in spleen, thymus, peripheral mononuclear blood cells, testis and ovary.
備注：圖片僅供參考。僅供科研，不可用于臨床。
