Pepsin: Difference between revisions

Theodor Schwann discovered [[Pepsin]] in 1836. He named the enzyme pepsis from the Greek word peptein which means to digest. Pepsin was the first animal enzyme to be discovered, and, in 1929, it became one of the first enzymes to be crystallized, by John H. Northrop.  

==Protein Function==

Once denatured, pepsin is unable to refold to an active native state upon returning from denaturing conditions. One proposed solution for this is that pepsin formation depends on a separate prosegment (PS) domain. When returning from the denatured state, the denatured pepsin first has to bypass a large folding barrier and then in the presence of PS  the native state can become thermodynamically stable. The PS therefore can catalyze pepsin folding by stabilizing the transition state <ref name="native" /> .

</StructureSection>

==3D structures of pepsin==

*'''Pepsin'''

**[[2h6s]], [[2qzw]] – CaPep residues 59-398 – ''Candida albicans''<br />

**[[1s2b]] – SlPep - ''Scytalidium lignicola''<br />

**[[1y43]] – Pep – ''Aspergillus niger''<br />

**[[1ibq]] - Pep – ''Aspergillus phoenicis''<br />

**[[1uh7]], [[1uh8]], [[1uh9]], [[2apr]] – RcPep – ''Rhizopus chinensis''<br />

**[[1mpp]] – Pep – ''Rhizomucor pusillus''<br />

**[[3app]] – PjPep – ''Penicillium janthinellum''<br />

**[[1er8]], [[3er3]], [[4er1]], [[4ape]], [[1ent]] – CpPep – ''Cryphonectria parasitica''<br />

**[[3lzy]], [[1oew]] – CpPep residues 90-419

*Pepsin complex with inhibitor

**[[2h6t]] - CaPep residues 59-398 + pepstatin<br />

**[[1eag]] - CaPep residues 59-398 + inhibitor<br />

**[[2qzx]] - CaPep residues 77-418 + pepstatin<br />

**[[2ifr]], [[2ifw]], [[1s2k]] – SlPep + peptide<br />  

**[[1wkr]] - Pep + pepstatin – ''Irpex lacteus''<br />

**[[4apr]], [[5apr]], [[6apr]] - RcPep + pepstatin<br />  

**[[2rmp]] - Pep + pepstatin – ''Rhizomucor miehei''<br />

**[[1nlu]], [[1ga1]], [[1ga4]] - PsPep + pseudo-iodotyrostatin – ''Pseudomonas''<br />

**[[1bxo]], [[1bxq]], [[2wea]], [[2web]], [[2wec]], [[2wed]] - PjPep + inhibitor <br />

**[[1ppk]], [[1apv]], [[1apw]], [[1ppl]], [[1ppm]] – PjPep + peptide analog

*'''Pepsinogen'''

**[[3lzy]], [[1oew]] – CpPep residues 90-419<br />

**[[3pb5]], [[3pbd]], [[3pbz]], [[3pcw]], [[3pgi]], [[3pi0]], [[3pld]], [[3pll]], [[3pm4]], [[3pmu]], [[3pmy]] – CpETPep + fragment chemotype<br />

**[[3pcz]] – CpETPep + benzamidine<br />

**[[3prs]], [[3pww]] – CpETPep + antiviral drug<br />

**[[3q6y]], [[1gvx]], [[1gvu]], [[1gvv]], [[1gvw]], [[1gvt]], [[2jji]], [[2jjj]] - CpETPep + pyrrolidine derivative<br />

**[[3er5]], [[4er4]], [[5er2]], [[2er0]], [[2er6]], [[2er7]], [[2er9]], [[5er1]], [[1epl]], [[1epm]], [[1epn]], [[1epo]], [[1epp]], [[1epq]], [[1epr]], [[3uri]], [[3url]]  – CpETPep + peptide<br />

**[[4er2]] - CpETPep + pepstatin<br />

}}

=References=