Proteins Flashcards
Alkaline (behave as anions) and acidic
(behave as cation)
Amphoteric
the pH at which an amino acid or
protein has no net charge
Isoelectric Point
Take Note for Isoelectric Point!
pH > than pI then overall charge is negative
pH < than pI then overall charge is positive
Caused by exposure to extreme temperature
Physical denaturation
Caused by exposure to highly acidic or highly
alkaline environment
Chemical denaturation
Pregnant women, growing children, and adults recovering from major illness (↑
intake > ↓ metabolite production) – during
buildup
Positive Metabolism
Excessive tissue destruction, such as burns, wasting diseases, continual high fevers, or starvation (↑ metabolite production
> ↓ intake)
Negative Metabolism
Biological catalyst; Markers of organ damage – leaks when organ damage is severe
Enzymes
Chemical messengers / signaling molecules; Control cells/organs/organ system
Hormones
Facilitate movement of ions, trace metals,
lipids and etc.
Transport Proteins
Prevents cell lysis by facilitating the entry and
exit of water in the cells
Osmotic Force
Marker of malnutrition (decreased uptake) and cystic fibrosis (increased excretion); Negative acute phase reactant; General transport protein
Albumin
AKA transthyretin – transporter of thyroid
hormones (T3 and T4); Elevated in alcoholism, chronic renal failure, steroid treatment
Prealbumin
Neutralizes neutrophil elastase (excess can
damage lungs); 90% of the α1-globulin fraction; Emphysema and cirrhosis; Elevated during inflammation, pregnancy, contraceptive
Antitrypsin
Protect fetus from immune system of mother; Decreased in Down’s Syndrome and Edward’s
Syndrome; Hepatocellular carcinoma – tumor marker; Lens culinaris agglutinin - can be used for affinity chromatography
α-Fetoprotein
Binds progesterone and cardioactive drugs; Cancer, inflammation, RA and AMI; RID and nephelometry
Acid glucoprotein / orosomucoid
Integral in formation of amyloid
deposits in the brain; Increased level in serum of patients with Alzheimer’s diseases and chronic obstruction pulmonary disease (COPD); Inactivates prostate specific antigen
Antichymotrypsin
A light chain and one or two heavy chains; Elevations in ITIs are often seen in
inflammatory disorders; Carcinogenesis
Inter-α-Trypsin Inhibitor
Major carrier protein for vitamin D, fatty acids
and endotoxins; Cochemotactic factor in facilitating chemotaxis of neutrophils and monocytes
Gc-Globulin/Vitamin D-binding protein
Binds free hemoglobin; Prevents removal of reusable components (iron and globin) in urine
Haptoglobin
Transports copper; Decreased in Wilson’s and Menke’s disease
Ceruloplasmin
Decreased copper since stored
coppers are excreted in urine and
deposited in tissues. Wilson’s or Menke’s?
Wilson’s
Impaired intestinal absorption
causing decreased copper levels; Kinky-hair disease. Wilson’s or Menke’s?
Menke’s
Copper deposited in cornea
Kayser-Fleischer rings
Entrapment of proteases; Largest globulin next to immunoglobulins
Macroglobulin
Bind and transport heme until it is converted
to bilirubin
Hemopexin
Light chain component of Human Leukocyte
Antigen (HLA) – marker
Microglobulin
Transporter of iron
Transferrin/Siderophilin
Major marker of non-specific inflammation; C substance/polypeptide
CRP
Recurrent antibody / marker of immunity; Can cross the placenta
IgG
First antibody to be produced in the
initial infection (largest antibody – pentameric
structure)
IgM
Present in secretions (dimeric)
IgA
Produced in allergic reactions/parasitic
infections
IgE
Not normally found in serum / attached
to B-lymphocytes (regulate B-cell function)
IgD
Take Note for Protein!
Turbidity due to lipemia can affect the
spectrophotometric analysis
Recumbent position: relaxed position (slight decrease)
Age – inversely proportional
Protein MOA: Nitrogen in the presence of oxygen is heated to high temperature; Ozone is added to form nitrogen dioxide; As nitrogen dioxide undergo decay, it emits a _
Chemiluminiscence
Albumin dye that is prone to interferences
(alpha-1, alpha-2 and beta-globulins)
Methyl orange
Albumin dye that has false elevation in antibiotics (penicillin, sulfonamide, conjugated bilirubin, aspirin)
2,4’-hydroxyaxobenzene-benzoic acid
(HABA)
Albumin dye that is prone to interference of hemoglobin, alpha-1 globulins (late-reacting)
Bromcresol green
Albumin dye that is prone to interference of presence of bilirubin in sample (high)
Bromcresol purple
Take Note for BCG/BCP
BCG/BCP prone to renal disease and
kidney failure (BCG – overestimation, BCP –
underestimation)
Globulin dye produces what color in the presence of Cu2+ and an acid medium?
Purple complex
Reference method for total protein determination
Kjeldahl
Kjeldahl Precipitation is done with?
Tungstic acid / trichloroacetic acid
Kjeldahl Digestion is done with?
Heat and sulfuric acid
Kjeldahl Boiling: What temperature and what can be used as catalyst?
340-360 degrees Celsius
Potassium sulfate
Kjeldahl Nitrogen Conversion
Addition of ammonium bisulfate then
distill with boric acid → ammonium borate
Reagent – ammonium mercuric iodide; End color – yellow complex
Nesslerization
Reagent – sodium nitroprusside, alkaline hypochlorite; End color – indophenol blue
Berthelot
Formation of copper complex with peptide
bonds (blue reagent – violet/purple complex end product)
Biuret
Prevents reduction of copper (maintaining of charge) – reduced copper is color red (prevents precipitation of copper into brick red precipitate)
Sodium potassium tartrate
Color developer for Biuret
NaOH
Prevents oxidation of copper (antioxidant) in Biuret
KI
Salt Fractionation – adding salts to remove globulins (example of salts)
Sodium sulfate
Stains used in Protein Electrophoresis
Bromophenol blue
Ponceau S
Amido black
Lissamine green
Coomassie brilliant blue
Total Protein is normal or decreased
Albumin is decreased
Globulin is increased
Hepatic Damage (Cirrhosis, Hepatitis, Obs Jaundice)
Burns, Trauma
Infection
Total protein is decreased
Albumin is decreased
Globulin is normal
Malabsorption
Inadequate Diet
Nephrotic Syndrome
Total Protein is decreased
Albumin is normal
Globulin is decreased
Immunodeficiency syndrome
Total protein is decreased
Albumin is decreased
Globulin is decreased
Salt retention syndrome
Total protein is decreased
Albumin is decreased
Globulin is increased
Dehydration
Total protein is increased
Albumin is normal
Globulin is increased
Multiple myeloma
Monoclonal and polyclonal gammopathies
Increased alpha-2 and beta-globulins
(increased lipoproteins)
Obstructive Jaundice
Increased in gamma fraction; Hepatocellular damage
Infectious hepatitis
Conversion Factor of Protein
10
