I generally know how antibodies work by binding to antigens, but what is the specific purpose to being Y-shaped, as opposed to any other shape? Does this aid their function? Thank you.

  • $\begingroup$ In a comment on this question, asking the poster what research had been performed before posting, I drew his attention to illustrations of antibody–antigen interaction in general articles about antibodies. In order to be inclusive to users of this site with visual impairments (who are perfectly able to use the web but may rely on screen readers) I added a rider. The fact that this comment was removed suggests the rider was interpreted as an insult to the poster of the sort "anyone who is not blind…". This was categorically not the case. $\endgroup$ – David May 21 '20 at 19:59
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    $\begingroup$ Having two antigen-binding sites allows agglomeration or clumping of antigens, which stimulates further immune response (phagocytosis). $\endgroup$ – Alex Reynolds May 21 '20 at 21:48

Antibodies also known as immunoglobulins consists of two heavy chains and two light chains linked via disulfide bonds to form Y-shaped structure (as shown in figure below).

This Y-shaped structure bestows antibodies with two properties. Firstly, antigen-binding through the antigen binding fragment(Fab); and secondly, interaction with immune cells and proteins through fragment crystallizable region (Fc) to stimulate and regulate host immune defense mechanisms.

Fc and Fab portions of the antibody molecule are joined by flexible hinge region which enables antibodies to interact with the antibody-binding proteins and thus help in mediating immune effector mechanisms. So, this Y-shaped structure provide proper flexibility for binding to antigens and proteins/immune cells of immune system.

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    $\begingroup$ Your answer is dominated by a graphic that is predominantly text. While graphics are often important to describing concepts in biology, in this case the parts of the graphic text that are necessary could (and should) have easily been written as text, making them accessible to users with visual difficulties. This might also have helped you focus on what was important in your answer. $\endgroup$ – David May 21 '20 at 20:04
  • $\begingroup$ Thanks for your advice, will keep it in mind from now onward. $\endgroup$ – Twinkle Sheen May 21 '20 at 20:09
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    $\begingroup$ IMHO, this does not explain the Y structure. Single chain Fragments (ScFv) also have an Fab and an Fc, and, due to their smaller size, can even better diffuse into tissue. $\endgroup$ – imalipusram May 22 '20 at 1:21

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