Structure
Proteins from the TGF-beta family are only active as homo- or heterodimer; the two chains being linked by a single disulfide bond. From X-ray studies of TGF-beta-2, it is known that all the other cysteines are involved in intrachain disulfide bonds. As shown in the following schematic representation, there are four disulfide bonds in the TGF-beta's and in inhibin beta chains, while the other members of this family lack the first bond.
interchain | +------------------------------------------|+ | || xxxxcxxxxxCcxxxxxxxxxxxxxxxxxxCxxCxxxxxxxxxxxxxxxxxxxCCxxxxxxxxxxxxxxxxxxxCxCx | | | | | | +------+ +--|----------------------------------------+ | +------------------------------------------+where 'C' denotes a conserved cysteine involved in a disulfide bond.
Read more about this topic: Transforming Growth Factor Beta Superfamily
Famous quotes containing the word structure:
“Why does philosophy use concepts and why does faith use symbols if both try to express the same ultimate? The answer, of course, is that the relation to the ultimate is not the same in each case. The philosophical relation is in principle a detached description of the basic structure in which the ultimate manifests itself. The relation of faith is in principle an involved expression of concern about the meaning of the ultimate for the faithful.”
—Paul Tillich (1886–1965)
“A structure becomes architectural, and not sculptural, when its elements no longer have their justification in nature.”
—Guillaume Apollinaire (1880–1918)
“The structure was designed by an old sea captain who believed that the world would end in a flood. He built a home in the traditional shape of the Ark, inverted, with the roof forming the hull of the proposed vessel. The builder expected that the deluge would cause the house to topple and then reverse itself, floating away on its roof until it should land on some new Ararat.”
—For the State of New Jersey, U.S. public relief program (1935-1943)