What Is The Difference between a protein and a peptide?
Proteins and peptides are
fundamental components of cells that carry out important biological functions.
Proteins give cells their shape, for example, and they respond to signals
transmitted from the extracellular environment. Certain types of peptides play
key roles in regulating the activities of other molecules. Structurally,
proteins and peptides are very similar, being made up of chains of amino acids
that are held together by peptide bonds (also called amide bonds). So, what
distinguishes a peptide from a protein?
The basic distinguishing factors are size and
structure. Peptides are smaller than proteins. Traditionally, peptides are
defined as molecules that consist of between 2 and 50 amino acids, whereas
proteins are made up of 50 or more amino acids. In addition, peptides tend to be
less well defined in structure than proteins, which can adopt complex
conformations known as secondary, tertiary, and quaternary structures.
Functional distinctions may also be made between peptides and proteins.
Peptides, however, may be
subdivided into oligopeptides, which have few amino acids (e.g., 2 to 20), and
polypeptides, which have many amino acids. Proteins are formed from one or more
polypeptides joined together. Hence, proteins essentially are very large
peptides. In fact, some researchers use the term peptide to refer specifically
to oligopeptides, or otherwise relatively short amino acid chains, with the term
polypeptide being used to describe proteins, or chains of 50 or more amino
So what are peptides?
By definition they are a
compound of two or more amino acids in which a carboxyl group of one is united
with an amino group of another. With the elimination of a water molecule, a
peptide bond is formed. In simple tearms they are basically small proteins.
Technically, anything with less than fifty amino acids is considered a peptide
but this is not set in stone. A dipeptide is made up of two amino acids joined
by one peptide bond. Tripeptides are three amino acids bound by two peptide
binds. And so on and so forth. A polypeptide is just a long, un-branched chain
of amino acids joined by peptide bonds that is not complex enough to be referred
to as a protein. (Proteins are made up of polypeptides.)
Peptides, as we mentioned are made from amino acids.
So, intake and production of all the amino acids is necessary for production of
all the peptides needed for the body to work efficiently. Of course, as we age
and we go through different times in our lives with different diets, stress, and
physical changes some essential amino acids and peptide production is
down-regulated. For example, insulin-like growth factor (IGF-1) production is
reduced naturally when we are stressed and as we age.
Peptides have many functions
in the body, some act like neurotransmitters, others like hormones. Many control
and influence how our bodies react to diet and physical exercise. There are also
several amino acids that are necessary in sufficient amount to produce hormones
like human growth hormone (HGH, pictured to the right). If you are not absorbing
or making enough of those amino acids, your production of that hormone will be
lowered. Those of us interested in fitness and athletic goals, of course, are
interested in counteracting these down-regulations so that we can maximize our
bodies ability to recover, perform, and meet athletic goals.
Of course, amino acid
supplementation is a pretty common among fitness buffs. However, peptide
supplementation is becoming more common. What is the advantage? First, peptides
are digested and used more readily by the body as they are smaller and your body
does not have to break down a larger protein molecule. Also, peptides are
thought to be more stable in the body and therefore more beneficial than the
more unstable, un-bonded amino acids.
Glutamine and creatine
peptides are very popular as you end up with quicker absorption, fewer side
effects, and more bang for you buck from these versions of the supplements.
There are also the more general amino acid peptide formulations available that
deliver a whole spectrum of amino acids in a pill or powder form. They usually
are referred to as ďpre-digestedĒ proteins or peptides. They may be beneficial
for many who are looking to ensure an adequate amount of amino acids in a
stable, more easily digested form.
There are also some much
more controversial peptides being discussed and used in the fitness arena. These
usually come in injectable forms and are banned by many athletic governing
bodies. Most of these injectable forms of peptides are taken to bump up the
production of HGH, which can increase lean body mass, lower body fat percentage,
and improve speed of recovery after workouts. IGF-1, GHRP-6, and Ipamorelin are
examples of these peptides. There are other peptides like Melanotan, used to
increase tanning of the skin, and SNAP-8, used to decrease wrinkling of the
skin. Most of these peptides are only legally available for research purposes or
in specific clinical situations - and for good reason. No one is completely sure
what happens to the human body when these products are utilized for long-term
So, how can peptides be of benefit to those of us
looking to maximize our fitness, our recovery, and our body composition?
Peptides may enable you to absorb more bioavailable amino acids and deliver more
quickly to cells after workouts. You may also glean some of the benefits of old
school supplements like creatine without the old school side effects like
cramping and bloating by using the newer peptide versions. And, if you are
lacking in some of the basic amino acids, you may enable your body to produce
certain substances like growth hormone, which will ultimately enable you to see
more results from all your efforts in the gym and in the kitchen.
Peptides and Skin
Peptides in skincare products
have come a long way and the new research about how they benefit skin is
remarkable. Some of the information out there is exagerated, but other aspects
of peptides for skin deserve your attention.
First, we need to start with the science: Peptides
are fragments of proteins. On their own, peptides are made up of amino acids.
When amino acids are combined in certain formations they create specific
peptides (and there are hundreds of peptides), and when peptides are formed in a
certain way, they make specific proteins.
Proteins are the fundamental building blocks of skin.
Without peptides, skin doesnít remain intact and the result is loss of firmness,
appearance of wrinkles, texture changes, and skin that doesnít bounce back as it
fascinating about peptides is that abundant research has clearly shown that each
of them works in very specific ways to target an exact skincare need. They also
teach skin to do what's required to help revitalize these building blocks, which
can help revive aging skin.
Peptides in Skincare: A Balanced View
Although there are intriguing reasons to consider
peptides as a significant part of a skincare formula as we did with our unique
Peptide Booster, we also want you to know there's a lot of hype around what they
can do. Sadly, the hype is often completely blown out of proportion. Peptides
can do amazing things for skin, but they do not replace what cosmetic corrective
procedures can do, as many companies have claimed over the years.
There's no single ingredient
solution for all the signs of aging and other skin problems we endure, and
peptides are no exception.
Promising new research has us
excited about using peptides in skincare products. Their ability to help
revitalize skin's building blocks so it becomes more resilient is a wonderful
asset for skin, but keep your expectations realistic, or you will be
most important for you to keep in mind is that as special as peptides are, they
need "friends" in the form of supporting ingredients to help address all the
needs of skin. Any skincare formula worthy of your hard-earned dollars must
include the specialized ingredients we talk about all the time such as
antioxidants, skin-replenishing ingredients, and skin-restoring-ingredients
(which includes peptides). Peptides can do a lot on their own, but they can't do
it all alone.
reminder (because its so important), when peptides are blended with
antioxidants, skin-soothing ingredients, and skin-replenishing ingredients they
can address multiple signs of aging and you will love the results!
Copper Peptide: Fact or Fiction
Speaking of a single skincare ingredient being
overly-hyped, copper peptide is certainly one of them. The spin begins with the
notion that skinís building blocks are assembled by copper. So, the logic would
follow that you must have copper peptide in your skincare products to get that
benefit. Although itís true copper peptide is a skin-restoring ingredient, there
are lots of other peptides with equally, if not more impressive, properties.
To keep it in perspective, although there are studies
showing the dramatic positive effects of copper peptide those studies rarely, if
ever, compare copper peptides to other peptides or other ingredients like potent
antioxidants. Itís important to realize that many ingredients have extraordinary
research proving their value for skin, not just copper peptide. Thatís the
pitfall of getting too wrapped up in one single ingredient. Skincare isnít that
thereís also research about copper being potentially toxic to skin. However,
this research is mostly about pure copper in the body not as a peptide applied
to skin. The negative effects are about what happens when copper is out of
balance, meaning too much copper is present.
The Bottom Line
Peptides can be a great addition to your skincare
routine because they can address so many skin concerns. But as with all
anti-aging ingredients, the best approach is to use a cocktail of great
ingredients, including antioxidants and skin-restoring substances (plus daily
broad-spectrum sun protection) to visibly improve the health and appearance of
for this information:
Cosmetics, May 2017, pages 1-14
ChemMedChem, August 2016, issue 16, pages 1850-1855
Bulletin of Experimental Biology and Medicine, May
2016, issue 1, pages 175-178
Journal of Drugs in Dermatology, April 2016,
supplemental, pages 63-71
Austin Journal of Pharmacology and Therapeutics,
August 2014, pages 1-9
Biological Trace Element Research, August 2013, issue
2, pages 268-274
Clinical Chemistry and Laboratory Medicine, April 2013, pages 1Ė8
Dermato Endocrinology, July 2012, issue 3, pages