Insulin, conserved site <p>Insulin is involved in the regulation of normal glucose homeostasis, as wellas other specific physiological functions [<cite idref="PUB00003972"/>]. It is synthesised as a prepropeptide from which an endoplasmic reticulum-targeting sequence is cleaved to yield proinsulin. Prosinsulin contains regions A and B separated by an intervening connecting region C. The connecting region is cleaved, liberating the active protein, which contains the A and B chains,held together by 2 disulphide bonds [<cite idref="PUB00003970"/>].</p>