RSS

Introduction to Protein Structures

Why three dimnetional structures matter?

Most of proteins must assume a certain shape (three dimensional structure) to function. For example, if you boil an egg, egg white becomes hard and opaque. This is because the heat destruct the proper sturcture of proteins (termed as "denature"). Thus knowing the three dimentional structure of proteins are very important to understand their functions.

How to play with protein graphics

If you want to use the interactive graphics display by clicking View Structure(jV3) on each eProtS entry page, you need to install Java Run-time Environment and a software called JOGL. See http://www.pdbj.org/PDBjViewer/index.html for details.

How to interpret eProtS entries

For example, the eProtS entry PDB:4INS contains the following text:

Protein Name

Insulin

Species

Sus scrofa (pig)

Biological Context

Insulin is one of the classical molecules of protein crystallography. Much of the work on this protein was done in the laboratory of Dorothy Crowfoot-Hodgkin who received the 1964 Nobel prize in chemistry for her determination of biochemically important molecules and has so far remained the only woman among structural chemists honored with a Nobel prize. Insulin is also one of the important hormones of the human body, produced by the pancreas, and insulin-related health problems, known as diabetes, are one of the most dominant health problems of the Western world; in third-world countries tuberculosis is much more of a problem. Insulin helps to let glucose enter into cells and if the body does not produce sufficient amounts of insulin (type I) or if the existing insulin cannot be properly used (type II) the net result is called diabetes. Diabetes can be treated with drugs and with additional supplies of insulin, but untreated diabetes can be fatal.

Structure Description

4ins4ins_x4ins_y

When insulin was first crystallized, reproducible growth of crystals had been a problem after "successful" purification. The reason was that insulin needed zinc for forming crystals and the zinc had been removed. Proinsulin is cleaved to form two separate chains. The zinc coordinates with a water and with the nitrogen of a histidine side-chain. Of course a metal ion needs more coordination partners than that. The remaining coordinating atoms are contributed from molecules related to the original one by the symmetry of the crystal. This explains why insulin crystals could not be obtained in the absence of zinc.

Protein Data Bank (PDB)

References

Source

Baker, E.N. Blundell, T.L. Cutfield, J.F. Cutfield, S.M. Dodson, E.J. Dodson, G.G. Hodgkin, D.M. Hubbard, R.E. Isaacs, N.W. Reynolds, C.D. al., et; "The structure of 2Zn pig insulin crystals at 1.5 Angstroms resolution."; Philos.Trans.R.Soc.Lond. B Biol.Sci.; (1988) 319:369-456 PubMed:2905485.

Others

UniProt:P01315

author: Arno Paehler


Japanese version:PDB:4INS

Protein Name

is the name of that protein

Species

is the biological species from which this protein was obtained.

Biological Context

describes the roles this protein plays in the cell or body.

Structure Description

explains the basic structural features of this protein, and how the structural information helped our understanding of the biological function of this protein.

Protein Data Bank (PDB)

lists the links to the PDBj summary page of this entry, and PDBjViewer.

References

When available, the original literature (Source) is listed, as well as additional information resources.

author

The name of the author(s) or translator(s) of this entry.