Question

Briefly describe the process of protein folding. In your description comment on the various models that help describe protein folding, the value of using a “Folding Funnel” to describe the folding process, and the role of chaperones and chaperoning in in vivo folding.

Answer 1

Ans - The process through which protines acquires there native 3-D structure , this is a biologically functional , it is an in an expeditious and reproducible manner. It is procees by which polypeptides flods in to functional 3-D structure and randam coils.Each protein exists in a random cail manner whe it translate from a sequence of mRNA to a linear amino acid chain. Polypeptides have linear chain structure as its passes through ribisomes the linear chian begins to fold in to 3-D structure. Folding is saposed to occur wvwn during translation of polypeptide chain.The amino acids interact to produce a defined three dimensional structure the folded protines are known as native state. The resulting 3-D structure is determined by primary structure or sequence of amino acids. Folding Funnel provides large number of pathways and intermediates for the protein to fold to the native state, rather than being restricted to a single mechanism. The discription of proteins folding by the leveling free energy is also consistent with 2nd law of thermodynamics.

Chapreons are a class of protiens that aid in the correct foldings of oter protiens in vivo. They exist in all compartments and intreact with pepides cain to allow the anative three dimensional conformation as they themselves are not in volved in the structure , they may assist in folding even when the nascent polypeptide is being sysnthesized by ribosomes. Molecular chaperones operates by binding to stabilize an unstable structure of protiens in its folding pathway. In this way they work by reducing unwanted aggregations of polypeptide chain that might slowdon the search otherwise for the proper intermediate and provide efficient pathway for correct conformations.