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Please do NOT make changes to this Sandbox. Sandboxes 30-60 are reserved for use by Biochemistry 410 & 412 at Messiah College taught by Dr. Hannah Tims during Fall 2012 and Spring 2013.

Contents 1 Papain 1.1 Introduction 1.2 Structure 1.3 Mechanism 1.4 Function 1.5 Inhibition 1.6 References

Papain

Introduction

is a cysteine protease that is stable and active under a wide range of conditions. The enzyme present in the leaves, latex, roots, and fruit of the papaya plant (Carica papaya).^[1] The papain proteins are synthesized as inactive precursors that become active within two minutes of the plant being wounded and the latex is expelled.^[2] The latex is dried and then purified to extract the active papain enzme. The enzyme was first studied and isolated in the 1960's. It has a 23.4kDa theoretical molecular weight and works at an optimum pH of 6-7 and optimum temperature of 60-70 degrees Celsius.

Structure

Papain's three-dimensional structure is at 1.65 Angstrom resolution. It consists of one polypepetide chain that is made up of 212 amino acids residues. There are three present in the enzyme that maintains the protein's structure.

spinqualitylabelsall models Papain (9PAP) Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Mechanism

Function

Inhibition

^{[3] [4] [5] [6]}

References

1. ↑ http://www.britannica.com/EBchecked/topic/441803/papain
2. ↑ http://www.worthington-biochem.com/pap/default.html
3. ↑ http://www.pdb.org/pdb/explore/remediatedSequence.do?structureId=1POP&params.chainEntityStrategyStr=all
4. ↑ http://en.wikipedia.org/wiki/Papain
5. ↑ http://www.pdb.org/pdb/explore.do?structureId=9PAP
6. ↑ http://www.sigmaaldrich.com/life-science/metabolomics/enzyme-explorer/analytical-enzymes/papain.html