PROTEINS Flashcards
Covalently linked polymers of amino acids
- Carboxyl group of one amino acid combines with the amino group of another amino acid
Proteins
Bonds between amino acids in protein
peptide bond
_____ is removed - peptide bond
Water
- N-terminal end - amino group free
- C-terminal end - carboxyl group free
Protein
● Different amino acids compose a specific protein in a linear manner.
Primary structure
● It is a folded primary structure
● The peptide chains are folded regularly and that is the time where there is a formation of ______ (2)
Secondary structure
α-helix and β-pleated sheets
Secondary structure
● Commonly formed structures stabilized by hydrogen bonds between the _____ (2)
amino acids within the protein
A secondary structure folded into a three-dimensional form.
Tertiary structure
A result from the interaction of side chains, which are stabilized through the hydrophobic effect, ionic attraction, hydrogen bonds, and disulfide bonds.
● Definitely a polypeptide
● Refers to the overall shape, or conformation, of the protein molecule.
Tertiary structure
● A combined tertiary structures or combined polypeptides
QUATERNARY STRUCTURE
CLASSIFICATION OF PROTEINS (COMPOSITION)
Simple
Conjugated
- Contain peptide chains that on hydrolysis yield only amino acids
• albumin
• SIMPLE
- Comprise a protein (apoprotein) and a nonprotein moiety (prosthetic group)
• Lipids, CHO, porphyrins, metals
CONJUGATED
■ Lipids ()
■ CHO ()
■ Porphyrins ()
■ Metals ()
lipoprotein
glycoprotein
hemoglobin
ceruloplasmin
CLASSIFICATION OF PROTEINS (FUNCTION)
THE BOSS EI
Transport proteins
Hormones
Enzymes
Blood coagulation
Osmotic force
Storage proteins
Structural proteins
Energy source
Immunoglobulins
FIVE FRACTIONS OF PLASMA PROTEINS
● Albumin
● α1-Globulins
● α2-Globulins
● β-Globulins
● γ-Globulins
● α1-Globulins
○ α1-fetoprotein
○ α-antitrypsin
○ HDL
● α2-Globulins
HaCeMa
○ Haptoglobin
○ Ceruloplasmin
○ α2-macroglobulin
β-Globulins
CT
○ Transferrin
○ C-reactive protein
γ-Globulins
○ Immunoglobulins
PREALBUMIN
• Also known as
transthyretin
• Also known as transthyretin
PREALBUMIN
• Migrates ahead of albumin
• Transport protein of thyroid hormones
• Binds with retinol-binding protein to form a complex that transports retinol (vitamin A)
• Rich in tryptophan
PREALBUMIN
• Present in highest concentration
- Colloid osmotic pressure
- Transcapillary escape rate
- Bind to various substances
ALBUMIN
• Malnutrition
• Liver disease
- Resulting in the inability of hepatocytes to synthesize albumin
• Gastrointestinal loss
- Inflammation and intestinal mucosal disease
• Loss in the urine in renal disease
HYPOALBUMINEMIA
• Seen in dehydration
- Relative increased
- Fluid administration will decrease albumin levels back to normal
HYPERALBUMINEMIA
ABNORMALITIES
________
- Absence of albumin
________
- Unusual molecular characteristics
- Genetic in origin resulting from an autosomal recessive
trait
- condition of having two types of serum albumin that differ in mobility during electrophoresis
Analbuminemia
Bisalbuminemia
• Consists of alpha1, alpha2, beta, and gamma fractions in electrophoresis
GLOBULINS
GLOBULINS
• Consists of (4) fractions in electrophoresis
alpha1, alpha2, beta, and gamma
• Acute-phase reactant
• Neutralize trypsin-like enzyme that can cause hydrolytic damage to structural protein
• Increased: inflammation, pregnancy, contraceptive use
• Deficiency: Severe, degenerative, emphysematous pulmonary disease
ALPHA 1 - ANTITRYPSIN
Done
• Synthesized initially by the fetal yolk sac and then by the parenchymal cells of the liver
- Peak: 13 weeks’ gestation
- Recede: 34 week’s gestation
• Can pass across the placenta
ALPHA 1 - FETOPROTEIN
• Spina bifida and neural tube defects
• Atresia of the gastrointestinal tract
• Fetal distress
• Ataxia-telangiectasia
• Tyrosinosis
• Hemolytic disease of the newborn (HDN)
• Tumor marker: hepatocellular carcinoma and gonadal tumors
ELEVATED AFP
ALPHA 1 - ACID GLYCOPROTEIN
• Also called as
orosomucoid
• Also called as orosomucoid
• Formation of certain membranes and fibers in association with collagen
• Acute phase reactant
• Increased:
- Inflammation, stress, AMI
- Cancer, Surgery
- Pneumonia
- RA
ALPHA 1 - ACID GLYCOPROTEIN
• Serine proteinase inhibitor (serpin)
• Inhibits some enzymes
• Acute phase reactant
• Increased:
- Inflammation
• Deficiency:
- associated with asthma and liver disease
ALPHA 1 - ANTICHYMOTRYPSIN
• Group-specific Component/Vitamin D-binding protein
• Increased:
- 3rd trimester of pregnancy
- Patients taking estrogen oral contraceptives
• Decreased:
- Liver diseases and protein-losing syndromes
• An alpha2-glycoprotein
• Synthesized by the liver and in RES
• Bind free hemoglobin by its alpha-chain
• Increased:
- Inflammation
- Burns
- Nephrotic syndrome
HAPTOGLOBIN
• Copper-containing, alpha2-glycoprotein
• Elevated: inflammation, infection, tissue damage and pregnancy
• Decreased:
- Wilson’s disease
• Hepatolenticular degeneration
• Autosomal recessive inherited disease
- Resulting to hepatic cirrhosis and neurologic damage
CERULOPLASMIN
• Found principally in the intravascular spaces
• Inhibits proteases
• Slightly increased: pregnancy and contraceptive drugs
• Increased:
- Nephrosis
- Diabetes
- Liver diseases
ALPHA 2 - MACROGLOBULIN
• Siderophilin
• Transports iron, can carry it to cells and prevents loss of iron through the kidney
• Increased:
- Microcytic, hypochromic anemia
• Decreased:
- Malnutrition, nephrotic syndrome, inflammation
TRANSFERRIN
• Removes circulating heme
• Decreased: hemolytic anemia
• Increased:
- Diabetes mellitus
- Duchenne-type muscular dystrophy
- Administration of diphenylhydantoin
- Inflammation
HEMOPEXIN
• Transport cholesterol, triglycerides and phospholipids
LIPOPROTEINS
• Light chain component of the major histocompatibility complex (HLA)
• Increased:
- Impaired kidney clearance
- Overproduction of acute-phase reactants
BETA 2 - MICROGLOBULIN
• Collective term for several proteins that participate in the immune reaction
• Link to the inflammatory response
• Increased:
- Inflammatory states
• Decreased:
- Malnutrition; SLE; DIC
COMPLEMENT
• Form a fibrin clot when activated by thrombin
• Not seen in serum
• Acute-phase reactant
• Increased:
- Pregnancy
- Use of birth control pills
• Decreased:
- Extensive coagulation
FIBRINOGEN
• Appears in blood of patients with diverse inflammatory diseases
• Rises:
- Tissue necrosis
- Pneumococcal infections
• One of the first acute-phase proteins to rise in response to inflammation
C- REACTIVE PROTEIN
• Synthesized in plasma cells
• IgG, IgM, IgA, IgE, IgD
• Synthesis is stimulated by an immune response to foreign bodies
IMMUNOGLOBULINS
• A heme protein found in striated muscles
• Can reversibly bind oxygen but requires a very low oxygen tension to release the bound oxygen
• Increased in AMI within 1-3 hours of onset and reaches peak concentration in 5-12 hours
MYOGLOBIN
Bind to the thin filaments of striated muscles
- Trop-T (TnT)
- Trop-I (Tnl)
- Trop-C (TnC)
TROPONIN
Regulate muscle contraction
Tropinin
TOTAL PROTEIN ABNORMALITIES
• Hypoproteinemia
• Hyperproteinemia
