Term
Heme:
-What is it as a group and on what proteins is it found
-# of coordination sites and their names
-Parts |
|
Definition
-Prosthetic group in hemoglobin and myoglobin where oxygen binds and releases
-6 coordination sites, 4 on pyrrole ring, proximal histidine, and empty, flexible position
-Porphyrin ring (4 linked pyrrole rings)and iron (Fe2+) |
|
|
Term
|
Definition
| -Dimer of dimer, two dimers with alpha and beta subunits |
|
|
Term
Heme:
Which AA's interact with which coordination sites |
|
Definition
His F8 (proximal H)-> covalent bonds to 5th position
His E7 (distal H) -> near 6th position (inhibits carbon monoxide bonding) |
|
|
Term
Allostery:
-Meaning
-Coopertivity
-Protein structure level
-T/R states |
|
Definition
-Changing structure, a change in protein's conformation means a change in property
-Cooperativity is a change in binding affinity caused by binding allostery
-Protein needs 4* structure to have allostery
-The binding of oxygen to hemoglobin's heme causes a change in conformation from the tense, T-state with low binding affinity to a relaxed, R-state with high binding affinity |
|
|
