Heat-Shock Proteins

Heat shock proteins (HSP) support the maintenance of three dimensional structures of proteins for instance by protecting them from denaturation due to heat. They can be found everywhere in the organism and are expressed extensively, for example, under stress condition caused by exposure to high heat, UV-rays or ethanol.

Image: formalin fixed paraffin embedded human breast carcinoma stained with HSP 70 antibody. ABIN115306

Many Heat shock proteins belong to the family of chaperons which play a role in protein translocation, and folding and assembly, also under standard conditions. Chaperons do not contain information about the protein specific three dimensional folding but generally accelerate and facilitate folding by inhibiting aggregation and defective bindings. HSPs are distinguished in categories according to their molecular weight.

The most researched heat-shock proteins are hsp60, hsp70 and hsp90. The numerical value is the molecular weight in kilo Daltons. Hsp60 is an important component of the chaperon system in animal organisms. Hsp60 recognizes collapsed substrate proteins, which would aggregate otherwise, and folds them actively under consumption of ATP. Hsp70 on the other hand helps to maintain the unfolded condition of target proteins.

The chaperone hsp90 family proteins are ubiquitous in prokaryotes and eukaryotes and apparently prevent the final steps of the protein folding process. Hsp90 interact with actin and tubulin and in concert with hsp70, as well as others, function as a supramolekular complex.

Hint: On antibodies-online.com you will find close to 500 antibodies specific for heat-shock proteins.