Plasma Proteins & Immunoglobulins

Question 1

B1-globulin glycoprotein

Answer 1

Transferrin

• 2 mols Fe per mol of Tf
• Tfr1 and Tfr2 - receptors that bind iron to facilitate endocytosis

Question 2

A2-globulin plasma protein

Answer 2

Ceruloplasmin

Question 3

1 mole of ceruloplasmin binds __ atoms of copper VERY TIGHTLY

Answer 3

6

Question 4

Transmembrane protein in enterocyte with ferroxidase activity

Answer 4

Hephaestin

• Converts ferrous to ferric for transport across plasma membrane

Question 5

Carries Fe across basolateral membrane

Answer 5

Ferroportin

Question 6

Transfers iron from apical surface of enterocytes into their interiors

Answer 6

DMT1 (Divalent Metal Transporter)

Question 7

Protein that stores iron (Fe3+, ferric) in enterocytes for future use

Answer 7

Ferritin

Question 8

High Fe levels: Fe _______ to IRE-BP that ________ binding of IRE to mRNA, leading to synthesis of _______ and degradation of ________

Answer 8

High Fe levels: Fe BINDS TO to IRE-BP that PREVENTS binding of IRE to mRNA, leading to synthesis of FERRITIN (storage of iron) and degradation of TfR

Question 9

Low Fe levels: Fe _______ to IRE-BP that ________ binding of IRE to mRNA, leading to synthesis of _______ and degradation of ________

Answer 9

Low Fe levels: Fe DOES NOT BIND to IRE-BP that ALLOWS binding of IRE to mRNA, leading to synthesis of TfR (Fe transport) and degradation of ferritin

Question 10

Osmotic pressure % d/t albumin

Answer 10

80%

Question 11

Major protein of human plasma

Answer 11

Albumin (60%)

• NOT glycosylated

Question 12

Plasma glycoprotein that binds extracorposcular Hb

Answer 12

Haptoglobin (Hb-Hp complex)

Question 13

Half life of Hp

Answer 13

5 days

Question 14

Half-life of Hb-Hp complex

Answer 14

90 mins

Question 15

Plasma protein not synthesized in the liver

Answer 15

Gamma-globulins (membrane-bound polyribosomes)

Question 16

Iron in enterocytes of proximal duodenum is in the (A) form due to the action of (B) enzyme

Answer 16

(A) ferrous state (Fe2+)

(B) ferrireductase

Question 17

Copper is carried by (A) to liver and leaves the liver through (B)

Answer 17

(A) albumin

(B) ceruloplasmin

Question 18

Disorder with mutation in ATP7A gene

Answer 18

Menke’s disease

ATP7A gene - copper-binding P-type ATPase

Question 19

X-linked d/o of copper metabolism

Answer 19

Menke’s disease

Question 20

Kayser-Fleischer ring

Answer 20

Wilson’s disease

Question 21

Mutation in ATP7B gene

Answer 21

Wilson’s disease

ATP7B protein - copper-binding P-type ATPase

Question 22

Drug that chelates copper

Answer 22

Penicillamine

Question 23

Genetic disease wherein copper can’t be excreted from bile and accumulates in the liver, brain, kidney, and RBC

Answer 23

Wilson’s disease

Copper toxicosis

Question 24

Inhibits trypsin, elastase and certain protease

Answer 24

α1-antiproteinase

Question 25

Principal serine protease inhibitor of human plasma

Answer 25

α1-antiproteinase

Question 26

Deficiency in α1-antiproteinase has a role in which disease?

Answer 26

Emphysema

Question 27

Largest plasma glycoprotein

Answer 27

α2-macroglobulin

Question 28

Transports 10% of zinc

Answer 28

α2-macroglobulin - synthesized in monocytes, hepatocytes, and astrocytes

Question 29

Major member of plasma proteins that include complement proteins C3 and C4

Answer 29

α2-macroglobulin

Question 30

Panproteinase inhibitor that binds proteinases and cytokines

Answer 30

α2-macroglobulin

Question 31

Accumulation of various insoluble fibrillar proteins between cells of tissues

Answer 31

Amyloidosis

Question 32

Plasma Igs are specialized cells of the _______ lineage

Answer 32

B cell

Question 33

Plasma Ig: CONSTANT region of half of light chain positioned towards ______ end

Answer 33

Carboxyl

Question 34

Plasma Ig: VARIABLE region of half of light chain

Answer 34

Amino terminal

Question 35

Linkage in plasma Igs

Answer 35

Disulfide bonds

Question 36

Plasma Ig: VARIABLE region of heavy chain

Answer 36

1/4 in amino terminal | 3/4 - heavy chain

Question 37

Functional regions of plasma Igs

Answer 37

2 Fab, 1 Fc Fab - antigen-binding fragments Fc - crystallizable fragment

Question 38

5 types of heavy chain regions determine the immunoglobulin class. What are the designated regions?

Answer 38

G, M, A, D, E

Question 39

All light chains are either ______ or ______ — never a mixture

Answer 39

Kappa or lambda

Question 40

Class-switching in Plasma Igs: Ab of ___ normally proceeds molecules of ___ class

Answer 40

IgM; IgG

Question 41

Downregulates intestinal absorption of iron from intestine, placental transfer, and release from macrophages

Answer 41

Hepcidin