Lecture 7 - Protein Function pt. 1

why is knowing 3D structure of protein useful

• can understand protein function from knowing 3D structure of protein

• protein structure is dynamic and sometimes goes through dramatic changes to perform biochemical function

ligand

small molecule that binds specifically with a larger one

binding site

crevice or pocket on a protein where the ligand binds

myoglobin (Mb)

• small globular hemoglobin (Hb)

  • 153 aa residue

• belongs to family of proteins called globins that have similar primary and tertiary structure

• is an a-protein that exhibits 8 a-helices (A-H) and 1 heme prosthetic group

  • has no B-sheets

• found in almost all mammals, localized primarily in muscle tissue

function of myoglobin

facilitates storage and diffusion of O2 since it has poor water solubility

what % of amino acids (aa) are identical in Mb and Hb in terms of their amino acids sequence?

only 18% of aa’s are identical

what does the Tertiary (3*) structure of Mb and Hb show?

they both fold into very similar 3D shapes