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Q: most abundant proteins in mammals ( No Answer,   3 Comments )
Subject: most abundant proteins in mammals
Category: Science > Biology
Asked by: ike9898-ga
List Price: $35.00
Posted: 23 Jul 2003 07:48 PDT
Expires: 22 Aug 2003 07:48 PDT
Question ID: 234169
Summary:  I need to know which are the most abundant proteins in the
whole body of a mammal (for example, I believe collagen is most
abundant protein in the body, based on either mass or number of copies
[yes, I know there are several types of collagen]).

Details:  I am most interested in the cow (Bos taurus), but I will pay
for information about any mammal.  I need at least the top 5 most
abundant, ranked (and hopefully with some information about amount or
% of total protein).  Information about protein abundance in
particular tissue types (other than muscle) would also help (what's
the most abundant prot in neural tissue?).

$25 for a minimal answer, but I will add a tip up to an additional $50
for an complete answer from credible references.

Clarification of Question by ike9898-ga on 28 Jul 2003 07:58 PDT
Increased price to $35 + generous tip as described in orginal question.

Clarification of Question by ike9898-ga on 28 Jul 2003 08:01 PDT
The information to answer this question may be in really old sources
(that is, not on the Net).  Maybe a really old biochem professor would
remember an old reference on this subject.

Request for Question Clarification by techtor-ga on 28 Jul 2003 08:58 PDT
I believe the data given by Tehuti is a most qualifiable answer.
Perhaps you could consider allowing that researcher to post their

Clarification of Question by ike9898-ga on 28 Jul 2003 14:35 PDT
I appreciate the data given in the comment, and the amount of work he
obviously did, but my question isn't answered.

Clarification of Question by ike9898-ga on 15 Aug 2003 05:47 PDT
Is there someone who would tackle this question if I increased the price to $60?
There is no answer at this time.

Subject: Re: most abundant proteins in mammals
From: tehuti-ga on 23 Jul 2003 13:31 PDT
Hello  ike9898

I’ve spent quite some time looking into this query and have been
unable to find an absolute ranking.

I have found definite statements that collagen is the most abundant,
followed by actin.  I have found claims that osteocalcin takes the 7th
place, and SOD the 5th.  Albumin, myosin, keratin and the globulins
are also strong contenders for places in the top 10.

Since I am unable to find a complete ranking as required by your
question, I am placing the information I have found as a comment
rather than as a full answer, because it might give other researchers
some leads in finding a definitive ranking.

“Collagens - fibrous glycoprotein family; functions only as part of
ECM [extracellular matrix] & only found there; most abundant human
protein (>25% of all protein); found throughout animal kingdom”
Chapter 7 of lecture notes, Cell and Molecular Biology, University of
Detroit Mercy 

“Collagenous proteins are the most abundant protein in the skeleton
and the body as a whole.
This large protein family has at least 19 distinct types, which are
coded by at least 34 genes (Ayad, S., R. P. Boot-Handford, M. J.
Humphries, K. E. Kadler, and C. A. Shuttleworth. 1998. The
Extracellular Matrix Facts Book. 2nd ed. Academic Press, San Diego,
CA.). Collagenous molecules contain three polypeptide (a) chains which
wrap into a triple helix. The peptide sequence within the collagen
triple helix is (Gly-X-Y)n where X and Y are often proline and 
hydroxyproline, respectively. These imino acids account for 20-25% of
the residues in collagens. The formation of hydroxyproline is a
post-translational event.”
From: “Role of the ECM in skeletal growth, development and health” by
Thomas M. Schmid
Rush Medical College, Chicago, IL 
On the web site of the Federation of Animal Science Societies

“Collagen is the most abundant protein in the animal body, and the
collagen which occurs in meat may be an important source of meat
toughness. Beef carcasses have to be graded by age mainly because of
age-related changes in collagen that cause meat from older cattle to
be tough.”
There follows a discussion of collagen and elastin in meat
Department of Animal and Poultry Science, University of Guelph, Canada
Contents page is at

“There are at least 20 different actin genes. However only six
different actin proteins have been identified in humans. It is
estimated that actin makes up 20% of the dry mass of muscle cells,
making it the second most abundant protein in the human body after
Lecture notes on Intracellular Structural Proteins, Dr Gillies,
University of Arizona 

“The smooth muscle (SM) {alpha}-actin gene activated during the early
stages of embryonic cardiovascular development is switched off in late
stage heart tissue and replaced by cardiac and skeletal
{alpha}-actins. SM {alpha}-actin also appears during vascular
development, but becomes the single most abundant protein in adult
vascular smooth muscle cells.”
From: “Impaired vascular contractility and blood pressure homeostasis
in the smooth muscle {alpha}-actin null mouse” by  Lisa A.
Schildmeyer, Renee Braun, George Taffet, Mariella Debiasi, Alan E.
Burns, Allan Bradley and Robert J. Schwartz
The FASEB Journal. 2000;14:2213-2220 

“Myosin is one of the most abundant proteins in the body.  There are
many types of myosin found in the body's cells.  Myosin-I and
myosin-II are the two most abundant subfamilies of myosin.  Myosin
class II is the most common type of myosin.  This type of myosin is
present in muscle tissues.  It is found in all of the body's muscle
types including the eyes, ears, and blood platelets.”
From: “Exploring Actin and Myosin” An interactive webpage for ISAT 454
by Brian Cunningham and Julie Schreiber (Department of Integrated
Science and Technology, James Madison University)

“Titin, also called connectin, is the largest protein known and is the
third most abundant protein in striated muscle behind only myosin and
From: . Cell Biol., Volume 143, Number 4, November 16, 1998 1013-1027
The NH2 Terminus of Titin Spans the Z-Disc: Its Interaction with a
Novel 19-kD Ligand (T-cap) Is Required for Sarcomeric Integrity
Carol C. Gregorio, Karoly Trombitßs, Thomas Centner, Bernhard
Kolmerer, Gunter Stier, Kathleen Kunke, Koichi Suzuki, Franz Obermayr,
Bernhard Herrmann, Henk Granzier, Hiroyuki Sorimachi, and Siegfried

“Keratins are the most abundant proteins in epithelial cells, and are
encoded by two groups of genes, type I and type II, which are distinct
at the level of genomic structure and nucleotide sequence.”
From “A Primer on Keratins”, Coulombe Laboratory, Dept Biological
Chemistry, Johns Hopkins 

Plasma: “The most plentiful is albumin, which transports several other
proteins and maintains blood pressure.
By itself, albumin makes up about 60 percent of the serum-protein
content, says Pounds. The 10 most abundant proteins—which include
antibodies, the iron transporter called transferrin, and
fibrinogen—account for more than 90 percent of all plasma protein.”
From “Blood Work” by John Travis, article in Science News Online, 15
March, 2003

“Only about 40% of serum albumin is contained within the circulation
at any one time; an
estimated 5% of the circulating albumin leaves the blood each hour to
be returned mainly by the
thoracic duct during the next 24-48 hours. Albumin pervades nearly
every fluid or secretion of
the body to some extent. The normal half-life of circulating albumin
is 19 days. This
corresponds to a daily degradation rate of about 14 grams, which is
about 20-30% of the total
protein synthesized by the liver. The degradation rate is in agreement
with the estimated
synthesis rate of 17 grams per day. From this it can be estimated that
the human liver makes
approximately 0.4 grams of albumin per hour.”
“Microfilaments, composed of globular actin subunits, play a role in
many cellular movement
processes including cell migration and cytosolic transport. Actin is
the most abundant protein in
eukaryotic cells ranging between 1-10% by weight of the total cell
protein. In the axon, actin
filaments are needed for membrane ruffling and cell movements at the
axon’s tip in the
elongation process.”
Notes from a workshop run by the University of Florida AntibodyApplications.pdf

“In human serum, albumin constitutes 50–70% of the total protein and
IgG constitutes 10–25%.”
Information from Amersham Biosciences

I’m less sure about the provenance of this statement:
“Concentration of the free radical control enzyme, superoxide
dismutase (SOD), in mammals is directly proportional to life span.
Humans have the highest concentrations of SOD. SOD is the fifth most
prevalent protein in the human body.(101,102) Elephants, parrots and
other long-lived species also have high levels. Thus, life expectancy
seems to be highly dependent on effective free radical regulation.”
The  statement appears in “Scientific Rationale for EDTA Chelation
Therapy -  Mechanism of Action” by  Elmer M. Cranton, M.D. and James
P. Frackelton, M.D.  and is adapted from A Textbook on EDTA Chelation
Therapy, Second Edition, 2001 edited by Elmer M. Cranton, M.D.,
Hampton Roads Publishing Company, Charlottesville, Virginia.
The citations upon which the statement is based are given as:
Demopoulos HB, Pietronigro DD, Seligman ML. The development of
secondary pathology with free radical reactions as a threshold
mechanism. Journal of the American College of Toxicology.
1983;2(3):173-184. and an oral presentation by Demopoulos.

“Osteocalcin is the seventh most abundant protein in the human body
and the second most abundant protein in bone tissue after collagen.”
“Osteocalcin (Lian J.B.& Gundberg,C.M. (1988) Clinical Orthopaedics
and Related Res. 226, 267-291.), or BGP, has only 49 amino acids, a 9-
charge and it is the seventh most abundant protein in the body. The
sequence of amino acids is highly conserved from swordfish to humans.
Bovine and human BGP only differ by two amino acids”
From “The Structure and Function of the Bone Protein Osteocalcin” 
Research grant proposal submitted by Richard V. Prigodich, Department
of Chemistry, Trinity College, Hartford, Connecticut. 

“▀-Trace protein (▀TP), recently identified as prostaglandin D2
synthase, is another brain-specific protein that is produced mainly in
the leptomeninges and the choroid plexus and is secreted into the CSF.
▀TP is the second most abundant protein in CSF after albumin. However,
it is also present in other body fluids, including serum, albeit at
much lower concentrations than in CSF”
From: “▀-Trace Protein as a Marker for Cerebrospinal Fluid Rhinorrhea”
Erich Arrer, Cem Meco, Gerhard Oberascher, Wolfgang Piotrowski, Klaus
Albegger and Wolfgang Patsch
Clinical Chemistry. 2002;48:939-941

“Changes in levels of myelin basic protein (MBP) as a marker of
myelin, neurofilament H (NFH) as a marker of axonal proteins, and
glial fibrillary acidic protein (GFAP) in astroglia after 2 months of
cerebral hypoperfusion were analyzed
….The major components of white matter are myelin, axon, and glia.
MBP, NFH, and GFAP were chosen as respective markers of these
components because of their abundance and functional importance. Thus,
MBP is the most abundant protein in the myelin sheath, NFH is one of
the major cytoskeletal proteins of the axon, and GFAP is a major
protein in the astroglia.”
From: White Matter Changes in the Gerbil Brain Under Chronic Cerebral
Takahiro Kurumatani, MD, PhD; Takashi Kudo, MD, PhD; Yasumitsu Ikura,
MD, PhD; ; Masatoshi Takeda, MD, PhD
Stroke. 1998;29:1058-1062

“Major Intrinsic Protein (MIP) is the most abundant protein of the
ocular lens fiber membrane and is a member of an ancient family of
membrane channel proteins”
The transcription factor Sp3 interacts with promoter elements of the
lens specific MIP gene
Sunghee Kim, Hong Ge, Chiaki Ohtaka-Maruyama, Ana B. Chepelinsky
Molecular Vision 1999; 5:12

“Thyroglobulin is the most abundant protein in the thyroid gland. Its
main function is to provide the peptide backbone for synthesis and
storage of thyroid hormones. It also offers a convenient depot for
iodine storage and retrieval when external iodine availability is
scarce or uneven.”
The Thyroid and its Diseases
Chapter 2                                                      
Thyroid Hormone Synthesis and Secretion
Revised by John T. Dunn, M.D., 1 September 2002
Subject: Re: most abundant proteins in mammals
From: aguved-ga on 16 Aug 2003 10:45 PDT
Probably the abundant proteins in mammals could be collagen,
hemoglobin, albumin,globulins, cytochromes, keratins e.t.c
Subject: Re: most abundant proteins in mammals
From: zzqqyt-ga on 19 Nov 2003 09:16 PST
This is a challenging question and it is entertaining to think about ...

I can only say that the question is unlikeley to get definitively answered.
There are experimental barriers to answering them which could be overcome, but
probably aren't worth it....

there are a lot of proteins, but the myriad (tens of thousands)of
protein products found in various cells can be measured quantitatively
by SDS PAGE gels and even be compared... (do a google search on 2D

a protein gel is run by basically liquefying the sample - suspending
it in a solution with detergent and then putting it over the gel.

note the two most mentioned proteins:
collagen is a connective protein which forms the matrix of skin and tissue
keratin is found in hair and horn

these proteins exist in a cross linked matrix - the biological
equivalent to plastic and analogous to lignin a molecule which makes
up most of wood and bark.  in one sense there is only one collagen
molecule in your entire skin... but more to the point it isn't going
to be taken in to solution to be run on a gel by mere detergent (we
can be thankful of that every time we wash our hands).

See: actin (and myosin) are the major components of muscle tissue - I
think maybe 30% ? by weight but it barely shows up on a 2D gel of
human heart: ... most of it got filtered out
because muscle makes pretty big fibers and is not so easily soluable.

So even if we did put a whole mouse in a blender (we certainly aren't
going to to do this for a human) there would be an insoluable pellet
at the bottom of the solution containing grams of many proteins such
as keratin and collagen which cannot be easily measured.

In fact each such protein would probably have to be studyed as to how
to identify, purify and estimate it separately. Such measurements have
been done - way back when, but they are probably buried in early 20th
century scientific literature and might suffer from their old
Still you can use some common sense - actin and myosin are a large
part of the muscle tissue, collagen is skin, and keratin is hair, fat
cells contain a lot of fat.  so the proportion of the body weight of
an individual can vary so much that the proportin of skin, muscle and 
hair can vary widely.

on the average: collagen, actin, hemoglobin (~4l of blood), myosin,
keratin are my top 5 in order.

if you say why you wanted this, perhaps there are better answers.

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