BABS1201 Enzyme Assignment Part 1
Jamieson Kerr: z5059573
Enzymes speed up biological rate of reaction by lowering the activation energy required to
start the reaction. The enzyme acts to lower the activation energy by weakening the bonds in
the substrate, meaning it requires less energy and time to break the bonds between substrate
and/or form new ones. Proteolytic enzymes are any of a group of enzymes that breakdown
long protein chains into shorter portions called peptides, and eventually into their
components, amino acids (Encyclopedia Britannica 2015). Bromelain is an enzyme that
digests proteins, so it is proteolytic.
Bromelain is found naturally in fresh pineapple and is commonly used to treat muscle injuries
and as digestive support (WorldHealth.net 2005). Bromelain is the shared name for
proteolytic enzymes found in numerous members of the family Bromeliaceae. The pineapple
Ananas comosus is the source of Bromelain studied most commonly (Biozym 2004). It has
been used in medicine by several native cultures for a long time, and was found chemically in
1876. It was first applied in pharmaceutics in 1957 as a therapeutic compound. Discoveries
with Bromelain such as antitumor properties, immunity modulation, digestive assistance,
enhanced wound healing, and cardiovascular and circulatory improvement show its diversity.
Studies have also revealed possibilities that plant proteases, especially Brolemain, could have
beneficial effects to Alzheimer’s disease patients.
Most studies in thermal stability have been performed using Bromelain from the stems of
pineapples as the highest enzyme concentration occurs in the lower portion of the mature
pineapple plant stems (Jutamongkon, R. and Charoenrein, S. 2010). It is most stable at pH 36 and at temperatures up to 60 degrees Celsius. Bromelain is a glycoprotein constituted of
one single polypeptide chain with 1 glycan per molecule with the number of amino acids
having not been properly established yet (Biozym 2004). Bromelain has a very reactive
cysteine, which is vital for catalysis, in the active centre. Therefore, the enzyme can be
activated by reducing compounds. But Bromelain can be irreversibly inhibited by some
alkylating agents. The optimum pH for catalytic activity is dependent on the nature of
substrate, type and concentration of buffer and if there is a reducing agent or not.
Gelatin contains a protein called collagen, which is a very important protein in many
mammals because its makes up about half of all the protein found in a mammal’s body. The
main macromolecule component found within gelatin is collagen. Since bromelain breaks
down collagen, it prevents it from congealing. Temperature and PH affect the effectiveness of
this enzyme, which is what will be tested in our experiment.
Hypothesis:
An alteration in temperature and pH will affect how well this enzyme works when breaking
down the gelatin, being most successful at around body temp and neutral pH.
References:
Biozym (2004). Datasheet – Bromelain. Accessed 11 April 2016. URL:
http://www.biozym.de/datasheets/bromelain.php
Encyclopedia Britannica (2015). Proteolytic enzyme. Accessed 11 April 2016. URL:
http://www.britannica.com/science/proteolytic-enzyme
World Health (2005). Posted on Dec. 30, 2005, 8:01 p.m. Accessed 11 April 2016. URL:
http://www.worldhealth.net/news/bromelain_pineapple_enzyme/
Jutamongkon, R. and Charoenrein, S. (2010). Effect of Temperature on the Stability of Fruit
Bromelain from Smooth Cayenne Pineapple - Nat. Sci. 44: 943 – 948. Accessed 11 April
2016. URL:
http://kasetsartjournal.ku.ac.th/kuj_files/2010/A1010081847262467.pdf