finals - protein 2 Flashcards
It is a small heme protein found in skeletal and cardiac
muscles.
myoglobin
It transports and stores oxygen from hemoglobin to
intracellular respiratory enzymes of contractile cells
myoglobin
It has higher affinity for oxygen than does
hemoglobin
myoglobin
It has a molecular weight of only 18 kDa, thus,
__ apparently leaks from damaged cells more
rapidly than other proteins.
myoglobin
It is a potential __ it has to be excreted when
plasma concentration exceeds reference ranges,
nephrotoxin
It is a marker for chest pain (angina) and early
detection of acute myocardial infarction (AMI).
EARLIEST MARKER OF HEART ATTACK
MYOGLOBIN
It is a useful marker for monitoring the success or
failure of reperfusion
myoglobin
Increased myoglobin are seen in
AMI, angina, rhabdomyolysis, muscle
trauma, extrenous exercise, intramuscular injection
and acute renal failure
myoglobin is measured by ____
It is measured in serum by immunoassay
At high levels in urine (myoglobinuria), it produces a
positive dipstick reaction for occult bloo due to
__
pseudoperoxidase activity
AMI value of myoglobin
> 100 u
These are complex of three proteins (regulatory
proteins) that bind to the thin filaments of cardiac
muscles.
Troponins (Tn)
These are regulators of actin and myos
troponins (Tn)
troponins that are present in both cardiac and skeletal
muscles
TnC, Tnl, TnT
___binds calcium ions that regulate muscle
contraction
TnC
Reference value of troponins
:< 0.1 ng/ml (< 0.1 ug/L)
The most important marker for cardiac injury
(AMI) they are derived from heart muscles
troponins
a troponin that is is a valuable tool in the diagnosis of AMI.
troponin T
It is a very sensitive indicator of even minor amount
of cardiac necrosis.
troponin I
It is highly specific for AMI - not elevated in renal
failure patients and no detectable amount in the
skeletal muscles.
troponin I
It is a cardiac marker. - marker for congestive heart failure
B-type natriuretic peptide (BNP)
It increases in response to peptide (BNP) ventricular
systolic and diastolic dysfunction and is diagnostic of
congestive heart failure
B-type natriuretic peptide (BNP)
It is a low molecular weight protein and a cysteine
proteinase inhibitor.
cystatin C
It is freely filtered by the glomerulus and completely
reabsorbed and catabolized by the proximal
convoluted tubule it is produced and destroyed at a
constant rate.
cystatin C
It has been included in the list of endogenous renal
marker owing for its sensitivity for determining the
glomerular filtration rate.
cystatin C
It has been proposed as an alternate test for serum
creatinine and creatinine clearance test to screen and
monitor kidney dysfunction
cystatin c
cystatin C may be especially useful in those cases where
creatinine measurement is not appropriate, such as
in__
liver disease, obesity or those with muscular
disease.
cystatin C may increased in
renal disease
cystatin C method of analysis
particle-enhanced immunoturbidimetry,
immunonephelometry
The presence of urine __ is generally
considered abnormal even in trace amounts.
albumin
Some healthy individuals exhibit albuminuria
following __
intense exercise
Urine protein of __ produces color change on
urine dipstick
26 mg/dl
Proteinuria (__) results from either glomerular or tubular dysfunction.
> 0.5g/day
It is an EARLY indicator of glomerular dysfunction and
precedes nephropathy associated with type 1
diabetes.
Microalbuminuria
Physiologic increase of microalbuminuria
physical exercise during the
previous 24 hours
Increased Microalbuminuria are seen in
diabetic nephropathy, fever, infection and
hypertension
CSF is an ultrafiltrate of plasma formed in the
__ of the ventricles of the brain
choroids plexus
Reference value of csf protein:
15-45mg/dL
CSF albumin: re range
10-30 mg/dL (2/3 of the CSF total
protein
It is inherited disorders of amino acid metabolism
Aminoacidopathies
It exist in either the activity of a specific enzyme in the
metabolic pathway or in the membrane transport
system for amino acids
Aminoacidopathies
It is an inborn error of metabolism characterized by
the absence of homogentisate oxidase in
Alkaptonuria
alkaptonuria
__ (tissue pigmentation)
Clinical feature: ochronosis
Diagnostic indicator of alkaltonuria
darkening of urine upon
standing at room temperature
It is characterized by impaired activity of cystathionine
B-synthetase.
Homocystinuria
It results to elevated levels of homocysteine and
methionine in blood and urine.
Homocystinuria
It is characterized by markedly reduced or absence of
a-ketoacid decarboxylase.
Maple Syrup Urine Disease (MSUD)
It results to accumulation of branched-chain amino
acids (leucine, isoleucine and valine) in blood, urine
and CSF
Maple Syrup Urine Disease (MSUD)
Clinical features of Maple Syrup Urine Disease (MSUD)
___
failure to thrive, muscular rigidity,
mental retardation, hypoglycemia
It is an autosomal recessive trait characterized by the
deficiency of the enzyme phenylalanine hydrolase
(PAH)/phenylalanine-4-mono-oxygenase,
which
catalyzes the conversion of phenylalanine to tyrosin
Phenylketonuria (PKU)
It is characterized by the presence of phenylpyruvic
acid (prime metabolite) in both blood and urine in
elevated concentration.
Phenylketonuria (PKU)
It is characterized by the deficiency of either of these
enzymes:
✓ tyrosine aminotransferase (tyrosinemia II);
✓ 4-hydroxyphenylpyruvic acid oxidase (tyrosinemia III);
fumarylacetoacetate FAA
hydrolase (tyrosinemia I)
Tyrosinemia
tyrosinemia
Deficiency of these enzymes would lead to __
liver
damage or cirrhosis
rough measure of all the proteins
in the plasma; can reflect nutritional status kidney,
and liver disease
Total protein test - rough measure of all the proteins
in the plasma; ca
An increase in total plasma proteins, is not an actual
disease state but is the result of the underlying cause,
dehydration
Hyperproteinemia
most common disorder in Hyperproteinemia
MULTIPLE MYELOMA
In plasma, both the total protein and non-protein
nitrogenous compounds, such as urea and creatinine,
are measured
Total Nitrogen
The method for total nitrogen analysis uses
___
CHEMILUMINESCENCE
The specimen most often used to determine the total
protein is __ rather than plasma (interference
may occur in presence of lipemia)
SERUM
The reference interval for serum total protein is ___ g/dL (65 to 83 g/L)
6.5 - 8.3
Digestion of protein;
measurement of
nitrogen content
Kjeldahl
Reference method for total protein determination
assume average nitrogen content of
16%
Kjeldahl
Measurement of
refractive index due
to solutes in serum
Refractometry
RAPID AND SIMPLE,
assume nonprotein
solids are present in
same concentration as
in the calibrating serum
Refractometry
Formation of violet
colored chelate
between Culons and
peptide bonds
Bluret
Routine method,
requires at least two
peptide bonds and an
alkaline medium
biuret
a total protein method that is only for Research use
Dye binding
albumin method
Labor
intensive
salt precipitation
albumin method
Globulins are
precipitated in
high salt
concentrations
albumin in
supernatant is
quantitated by
biuret reaction
salt precipitation
albumin
Sensitive
overestimates
low albumin
levels, most
commonly
used dye
BCG (bromocresol green
albumin method
Specific, sensitive, precise
BCP (bromocresol purple)
albumin methods
Accurate gives overview of
relative changes in different
protein fractions
Proteins
separated
based on
electric char
Electrophoresis
It is a process wherein filter paper is used as an
anticonvection support medium thus permitting
separation of the protein fractions into discrete bands
or zones.
Zonal Electrophore
Among the solid support media, __ and ___ have predominated in the laboratory due to
their ease of use, low cost and commercial
availability.
cellulose acetate and agarose
Standard dyes used in Electrophoresis
For serum protein electrophoresis
➢ Coomasic Brilliant Blue
➢ Ponceau S
➢ Amido Black
Standard dyes used in Electrophoresis
For lipoproteins
➢ Oil Red 0
➢ Sudan Blac
Standard dyes used in Electrophoresis
For glycoproteins
➢ Periodic Add Schiff
Gel Filtration
Column Separation
The order of protein elution is by molecular weight or
size from largest first to smallest last.
Column Separation
it is necessary to apply the sample in a small and
uniform volume because all protein species
continuously move through a gel filtration column all
at the same time but with different rates.
Column Separation
It is based on the charge of proteins which binds to
heads of a charged support medium
Ion Exchange Chromatograph
Serum Protein Electrophoresis (SPE)
principle
Migration of charged particles in an electric
field
The single most significant clinical application of SPE
is
for the identification of monoclonal spike of
immunoglobulins and differentiating them from
polyclonal hypergammaglobulinemia.
Serum Protein Electrophoresis (SPE)
___ produces a pattern of acute
inflammation associated with tissue injury, is elevated acute phase reactants (AAT, haptoglobin,
alpha-1 antichymotrypsin).
Myocardial infarction
Normal SPE Patter
albumin
a1
a2
beta
gamma
fastest band - most anodal
protein
albumin
glycoproteins,
AAT, AAG, thyroxine binding-globulin (TBG). It
increases as a non-specific response to inflammation.
Alpha 1- Globulin (2nd fastest band
haptoglobin, AMG, ceruloplasmin A
Alpha 2-Globulin (3rd band fastest band)-
transferrin, beta
lipoprotein, hemopexin, complement (C3 and C4)
Beta-globulin (4th band)
(5th band; slowest band) -
immunoglobulin and CRP
Gamma-globulin
Abnormal Serum Electrophoretic Patterns
Gamma spike
Multiple myeloma
Abnormal Serum Electrophoretic Patterns
Beta-gamma bridging:
Hepatic cirrhosis
Abnormal Serum Electrophoretic Patterns
a2-globulin band spike
Nephrotic syndrome
Abnormal Serum Electrophoretic Patterns
al-globulin flat curve
Juvenile cirrhosis (AAT
deficiency
Abnormal Serum Electrophoretic Patterns
Spikes of a1, a2 and B globulin bands
inflammation
It is an alternative test to chemical analysis of
serum total proteins. It is based on measurement
of refractive index of solutes in serum
Refractometry
These methods utilize sulfosalicylic acid and or
trichloroacetic acid. Measurement depends on
the formation of a uniform fine precipitate which
scatters
incident
light
in
suspension
(nephelometry) or block light (turbidimetr
Turbidimetric and Nephelometric Methods
Globulins can be separated from albumin by salting
out procedures using sodium sal
Salt Fractionation
Salt Fractionation
Reagent: __
sodium sulfate salt
in salt fractionation, it precipitates what and what is the supernant?
precipitates globulin
supernation albumin
It is the hereditary absence of albumin or
inability to synthesize albumin.
Analbuminemia
It is the presence of two albumin bands
instead of a single band in electrophores
Bisalbuminemia
It is the presence of albumin with unusual
molecular characteristics in the blood.
* It is associated with excess amount of
therapeutic drugs in serum
Bisalbuminemia
It is determine to validate if globulin is higher than
albumin.
Albumin / Globulin Ratio
If globulin is greater than albumin it is known as inverted A/G ratio seen in ___
cirrhosis, multiple myeloma and Waldenström’s macroglobulinemia.
Reference value of AG ratio: __
1.3-3:1
