Mammalian waxes are formed through an esterification reaction between long chain fatty acids and long chain alcohols. They are produced in sebaceous glands, ceruminous glands, and Meibomian glands. The key enzymes involved are fatty acyl-CoA reductase 1 and 2, which reduce fatty acids to fatty alcohols. Wax synthase then catalyzes the formation of wax esters. Mammalian waxes provide protection, waterproofing, and insulation. They also have antibacterial properties and uses in cosmetics and perfumes.
3. 1 Introduction
Waxes are monoesters of long chain
fatty acid and long chain alcohol and
are formed by esterification reaction.
4. Sites of Production
Sebaceous Glands
Located on the dermis.
These glands are
associated with the
production of sebum.
Ceruminous Gland
They are modified apocrine gland and
they produce cerumen alongwith
sebaceous gland
01 02
03
Meibomian Gland
Located in the upper and
the lower eyelids.
5. In general waxes can be obtained from
the reaction of a saturated /unsaturated
/polyunsaturated fatty acid with
monohydric alcohol
Saturated Fatty Acid: Palmitic Acid (16:0)
Polyunsaturated Fatty acid: LinoleicAcid (18:2)
Fatty alcohols usually have an even number
of carbon atoms. Some are unsaturated and
some are branched
Octadecanol(C18)
TheBuilders
Unsaturated Oelic acid (18:1)
6. Mechanism of wax
formation 2
The key enzymes that are involved in the
production of mammalian waxes are Fatty
Acyl-CoA Reducatse (FAR) and Wax
Synthase
7. The synthesis of wax
monoester takes place in
two catalytic steps where
the first step involves a
reduction reaction and the
second step involves a
trans-esterification reaction.
8. In mammals
The Fatty Acyl CoA reductase
enzyme is an iso-enzyme
FAR-1 : The Enzyme that can reduce both
saturated and unsaturated fatty acids.
(Can act on varying chain length and different
degree of unsaturation)
FAR-2 :The Enzyme which would reduce only
saturated fatty acid (acts on chains of length
C16-C18)
The peroxisome is associated
with the production of FAR-1
and FAR-2
Carbon
source
Fatty Acyl-ACP
Fatty Acid
Fatty aldehyde
Fatty Alcohol
Wax Ester
Acetyl-CoA
Fatty Acyl-CoA
9. More about Enzymes
• The enzymes FAR- 1 and FAR-2
within mammals have ~58% similarity
(as analysed by in silico model),
indicating that they have common
evolutionary ancestor.
• FAR-1 is more abundant in
preputial glands and FAR-2 is
more abundant in sebaceous
glands.
• The gene that encodes for FAR-1
is located on chromosome 7 and
the gene for FAR-2 is loacted on
chromosome 6
• The gene that encodes FOR WAX
SYNTHASE is found on the X-
Chromosome
• The enzyme WAX SYNTHASE
is found in the endoplasmic
reticulum and it requires certain
transport proteins to mediate its
transfer to the cytosol
10. Fact O-pedia
The enzymes that are responsible for the
conversion of fatty acyl- CoA have not yet
been discovered. They have been
hypothesized using various in silico models
3
11. Wax ester SQUALENE
found in whales/sharks is
known to have anti cancerous
properties
VERNIX CASEOSA is the
waxy coating over the fetus
that develops during the third
trimester
The Harderian gland’s
waxy secretion makes up
the nictating membrane in
mammals.
“Theory
A
widely
accepted
hypothesis
that
stands
the
test
of
time.
Theories
are
often
tested,
and
usually
not
rejected
”
12. 4
Uses and
Significance
• They have powerful antibacterial properties
and is effective against both gram positive
and gram negative bacteria .e.g. sapienic
acid from sebum.
• The grease/wax obtained from the wool of
sheep is used in cleaning or refining process.
• In marine mammals like whale they provide
insulation, buoyancy and even echo location.
• Spermaceti from sperm whale is used for
making cosmetics. E.g. Ambergris obtained
from the stomach lining is used in making
perfumes.
13. • Moon, Y. A., & Horton, J. D. (2003). Identification of Two Mammalian Reductases Involved in the Two-
carbon Fatty Acyl Elongation Cascade. Journal of Biological Chemistry, 278(9), 7335–7343.
https://doi.org/10.1074/jbc.m211684200
• Cheng, J. B., & Russell, D. W. (2004). Mammalian Wax Biosynthesis. Journal of Biological Chemistry,
279(36), 37789–37797. https://doi.org/10.1074/jbc.m406225200
• Gurr, M., I., Harwood, J. L., & Frayn, K. N. (2021). Lipid Biochemistry. An Introduction (Ebook PDF).
Springer book archive.
• Christie, W. W. (2021). Waxes - plant, sebaceous gland, insect, wool, surface, marine, whales - structure,
occurrence, biochemistry and function. Lipidmaps.Org.
https://lipidmaps.org/resources/lipidweb/lipidweb_html/lipids/simple/waxes/index.htm
• Waxes | Cyberlipid. (2021). Cyberlipid.Com. http://cyberlipid.gerli.com/description/simple-lipids/waxes-
2/
References
