8) Proteins Flashcards
(110 cards)
1
Q
basic protein formula
A
RCH(NH2)COOH
2
Q
isoelectric point (pI)
A
the pH at which the amino acid or protein has no net charge, and the positive charges equal the negative charges
3
Q
At a pH ——– than the pI, the protein carries a ——– charge
A
greater – negative
less – positive
4
Q
peptide bond
A
Chemical bond between a carboxyl group of one molecule and an amino group of the other molecule, releasing water
5
Q
Plasma ——— provided by the proteins tends to retain water in the vascular space
A
colloid osmotic pressure (COP)
6
Q
3 main functions of plasma proteins
A
- Maintenance of water distribution between cells and tissue.
- Coagulation proteins are important in maintenance of hemostasis.
- Transport vehicles to move various ligands to where they are needed or stored.
7
Q
Rare inherited disease involving the homogentisic acid oxidase
Leads to a buildup of homogentisic acid in the tissues of the body
A
alkaptonuria
8
Q
darkening of the tissues of the body because of the excess homogentisic acid
A
Ochronosis
9
Q
Caused by the absence or very low levels of the branched-chain enzyme α-keto acid decarboxylase complex
A
MSUD
10
Q
Results in the abnormal metabolism of three essential amino acids:
leucine, isoleucine, and valine
A
MSUD
11
Q
Results in the inability to metabolize the essential amino acid phenylalanine
A
phenylketonuria
12
Q
grouping of plasma proteins
A
- Albumin
- Globulin (α1 globulins, α2 globulins, ß1 globulins, λ globulins)
13
Q
TP =
A
albumin + globulin
14
Q
Main clinical significance of ———- is role as a sensitive marker of poor nutritional status such as protein-energy malnutrition (PEM).
A
prealbumin/transthyretin (TTR)
15
Q
protein measured in CSF, not electrophoresis
A
prealbumin/TTR
16
Q
albumin is approximiately —-% of serum protein
A
60
17
Q
list the 16 plasma proteins
𝛼1 - 3
𝛼2 - 3
β - 5
𝛾 - 2
A
prealbumin
albumin
—
𝛼1-antitrypsin
𝛼1-acid glycoprotein
alpha-fetoprotein
—
haptoglobin
ceruloplasmin
𝛼2-macroglobulin
—
transferrin
hemopexin
β-lipoproteins
β2-microglobulin
C3
—
fibrinogen
—
C-reactive protein
Ig
18
Q
albumin functions
A
Maintain plasma colloid osmotic pressure.
Bind and transport a wide variety of ligands.
Serve as an endogenous source of amino acids.
19
Q
causes of hypoalbuminemia
A
- increased catabolism (most common)
- impaired synthesis
- increased protein loss
- analbuminemia
20
Q
causes of hyperalbuminemia
A
- Dehydration/decreased plasma volume
- high protein diet
- albumin infusion
21
Q
A/G ratio
A
albumin/globulin
globulin = TP - albumin
22
Q
RR for A/G ratio
A
0.8-2.2
23
Q
Major α1–globulin, making up approximately 90% of α1–proteins.
A
α1–Antitrypsin (AAT)
24
Q
one of the most common genetically lethal diseases in Caucasians (1:4000)
A
AAT deficiency
25
sx of AAT deficiency
emphysema with onset at 45 years of age or earlier
emphysema occurring in the absence of smoking
26
is the major glycoprotein increased during inflammation, an Acute Phase Reactant (APR).
α1–Acid Glycoprotein/orosomucoid
(AAG)
27
Principal fetoprotein (fetal albumin-like protein) in maternal serum
alpha-fetoprotein
28
Used to screen for the antenatal diagnosis of neural tube defects including spina bifida and anencephaly
AFP
29
------ is decreased in Down’s syndrome and Trisomy 18
AFP
30
increased levels found in 80% of patients with hepatocellular cancer, 50% of germ cell tumors (gonadal), and all children with hepatoblastoma
AFP
31
An acute phase reactant that binds free hemoglobin in plasma
haptoglobin (Hp)
32
Depletion is the most sensitive indicator of intravascular hemolysis, in transfusion reactions, and certain hemolytic anemias.
Hp
33
Principal copper (Cu)-containing protein in plasma containing 95% of the total serum copper
Ceruloplasmin (Cp)
34
Decreased in Wilson’s disease, Menkes disease, malnutrition, malabsorption, severe liver disease, nephritic syndrome
Cp
35
Rare autosomal recessive trait where Cp levels are reduced and the dialyzable Cu concentration is increased.
Wilson disease
36
copper chealators used to tx Wilson's
penicillamine
trientine
37
effects of Wilson's disease
- Degenerative cirrhosis
- Chronic active hepatitis
- Renal tubular acidosis
- Neurological damage (clumsiness, tremors)
- Kayser-Fleischer rings, pigmented rings at the outer margins of the cornea and the sclera
38
In nephrotic syndrome, ------ is characteristically increased above normal because it is retained while smaller proteins are excreted in the urine.
AMG
39
Major component of β-globulins
negative acute phase reactant
TRF
40
Principal plasma protein for transport of iron as **Fe+3 — the ferric ion** — to storage sites, where it is bound to apoferritin and stored as ferritin
TRF
41
Important in the differential diagnosis of anemias and monitoring the treatment of iron deficiency anemia
TRF
42
A commonly used indicator of iron overload—screen for hemochromatosis
TRF
43
When red blood cells are destroyed, it transports **heme** to the liver, where it is catabolized by the reticuloendothelial system.
hemopexin
44
Increased levels are found in pregnancy and in diabetes mellitus.
hemopexin
45
Comprises the common light chain of human leukocyte antigens (HLA) found in all nucleated cells
BMG
46
Used for staging MM and for CLL survival
BMG
47
Increased in renal failure, inflammation, and neoplasms—especially those associated with B-lymphocytes
BMG
48
Collective term for 30 glycoproteins that participate in the immune reaction and serve as a link to the inflammatory response
C3
49
Plasma — sharp peak between Beta and Gamma region on electrophoresis (artifact)
fibrinogen
absent in serum
50
An acute phase reactant and a nonspecific indicator of bacterial vs viral infection, inflammation, and tissue injury or necrosis
CRP
51
Reacts with proteins present in many bacteria, fungi, and protozoan parasites
CRP
52
Levels rise dramatically following myocardial infarction, trauma, psychological or physical stress, infection, inflammation (e.g., rheumatic fever, rheumatoid arthritis), surgery, and various cancers.
CRP
53
undetectable in healthy individuals
CRP
54
Spike in Waldenstrom’s Macroglobulinemia
IgM
55
can rarely see an ----- spike in MM
IgA
56
Increased in infections, liver disease,
connective tissue disorders
IgD
57
----- proteins move toward the cathode (right)
gamma
58
Transitory --------- elevations in pre-eclampsia of pregnancy and dehydration.
urinary protein
59
indicator in protein pad of urine strip
tetrabromophenol blue
60
urinary protein elevation causes
pregnancy
nephritic syndrome
acute and chronic glomerulonephritis
renal failure
lesions of the kidney
multiple myeloma
61
RR for CSF protein
15-45 mg/dL
62
Increased CSF protein levels indicate...
a broken blood/brain barrier
63
Associated with a positive nitrogen balance
hyperproteinemia
(hemoconcentration or dehydration)
64
characteristic electrophoresis pattern of MM
monoclonal spike in gamma region
65
Caused by a negative nitrogen balance
hypoproteinemia
66
Based on presence of peptide bonds found in all proteins.
biuret reagent
67
When a solution of protein (serum or plasma) is treated with cupric (Cu+2) divalent ions in a moderately alkaline medium, a violet-colored chelate, which absorbs light at ----- nm, is formed between the cupric ion and carbonyl oxygen and the amide nitrogen atoms of the peptide bond.
540
68
Sodium potassium tartrate
Copper sulfate
Potassium iodide
NaOH
biuret reagent
69
dye-binding method of protein analysis uses ----------, which is dissolved in an acidic solution, causing it to absorb at 465 nm
Coomassie Blue G-250
70
RR for serum protein
6.0-8.3 g/dL
71
A physiological decrease of approximately 0.5 g/dL protein occurs in .....
bedridden patients
72
2 methods used for albumin
Bromocresol green
Bromocresol purple
73
4 requirements for dye-binding albumin methods
1. **Specific** binding of the dye to albumin in the presence of serum or plasma proteins
2. High binding **affinity** between the dye and albumin
3. Substantial **shift in the absorption wavelength** of the dye in the bound form
4. Absorption maximum for the bound form at a wavelength **distinct** from those where bilirubin and hemoglobin, the main **interfering** chromogens, can interfere
74
zwitterion
A molecule or ion having separate positively and negatively charged groups, with net zero charge
75
relative protein %
relative % = absorbance of one band/absorbance of all bands
76
high resolution electrophoresis
divides Beta band into 2
77
Electrophoresis pattern shows a double albumin spike
bisalbuminemia
78
a condition in which abnormal proteins (antibodies) of one type are found.
monoclonal gammopathy
79
a condition in which results from an increased production of several different immunoglobulins.
polyclonal gammopathy
80
- Patient’s serum has an M-protein that measures <3 g/dL
- Bone marrow that contains <10% of plasma cells
- no CRAB
Monoclonal Gammopathy of Undetermined Significance (MGUS)
81
- Patient’s serum has an M-protein that measures ≥3g/dL
- Bone marrow that contains ≥10% of plasma cells
- no CRAB
Smoldering Multiple Myeloma (SMM)
82
Plasma cells light chains (pieces of antibodies) misfold and build up in organs, causing them to thicken and loose function
amyloid light-chain (AL) amyloidosis
associated with SMM
83
Neoplastic proliferation of a clone of plasma cells
multiple myeloma
84
b cell tumor
plasmacytoma
85
hallmark of MM
lytic bone lesions
86
free light chains in urine associated with MM
Bence Jones proteins
87
Calcium (hypercalcemia)
Renal insufficiency
Anemia
Bone lesions/pain
88
Overproduction by B lymphocytes, mainly **in lymph nodes**
Waldenstrom’s Macroglobulinemia (WM)
89
Starts with an IgM MGUS
WM
90
Enlarged lymph nodes
Rouleaux formation on peripheral smear
↑ ESR
WM
91
Can precipitate and act as a cryoglobulin at low temperatures
Raynaud's phenomenon
cold urticaria
WM
92
Can lead to Hyperviscosity syndrome
WM
93
adverse effects of hyperviscosity syndrome
* Bleeding/vascular insufficiency
* Visual impairments
* Cardiac Insufficiency
* Neurological side effects
* Analyzer Issues
94
Precipitated out upon heating to 50-60°C and redissolved upon further heating to 90-100°C
Bence-Jones proteins
95
Motion of a liquid when a voltage is applied between the ends of an insulating tube that contains that liquid
electroosmosis
96
methodologies used to ID protein levels and M spikes
1. Electrophoresis (SPEP or UPEP)
2. Immunotyping (IT)
3. Immunofixation electrophoresis (IFE)
97
principle of IT
Disappearance of the abnormality in the antiserum-treated pattern indicates the presence of a monoclonal protein.
98
used to type any suspected monoclonal component previously detected by serum protein electrophoresis
Immunofixation Electrophoresis (IFE)
99
IEF techniques are similar to electrophoresis except that the separating molecules migrate through a pH gradient.
isoelectric focusing
(not done anymore)
100
------ is the most common cause of β-γ bridging.
cirrhosis
101
Excessive loss of serum proteins into the GI tract
protein losing enteropathy (PLE)
102
Results in hypoalbuminemia → poor surgical outcomes → risk of death
PLE
103
Fecal excretion of alpha 1-antitrypsin
PLE
104
↓ albumin
↑ 𝛼2
↑ 𝛾
chronic inflammation
105
↓ albumin
↑ 𝛼2
variably ↑ β
↓ 𝛾
nephrotic syndrome
106
↓ albumin
↑ 𝛾
briding
hepatic cirrhosis
107
↓ 𝛾
hypogammaglobulinemia
108
↓ albumin
↑ 𝛼2
↓ 𝛾
protein-losing enteropathy
109
↓ albumin
↑ 𝛼1
↑ 𝛼2
acute inflammation
110
↓ albumin
↑↑ 𝛾 spike
monoclonal gammopathy
