AAs and Protein Structures M2C

proteins are made of ______.

amino acids

amino acids are joined by ______ bonds.

peptide

amino acids are classified by:

polarity/neutrality, hydrophobic/hydrophilic (based on property of side chains)

doesn’t have charge, is hydrophobic

neutral and non-polar

doesn’t have charge, is hydrophilic

neutral and polar

charged (pos or neg)

hydrophilic, can form ionic bonds/salt bridges

_____ is start amino acid for all proteins.

methionine

_____ is a common target for post-translational modifications because of its free hydroxyl group

serine

all ______ are hydrophobic.

aromatics

if one amino acid is substituted for another, it is less likely to be problematic if the amino acids have ______ _______, but size, shape, and ability to accept modifications also matters

similar properties

hemoglobin structure

4 units: 2 alpha and 2 beta, both coded by different genes

what affects protein folding?

• bonds

• allosteric (spatial effects)

• environment (acidic, hot, cold, basic)

• binding of co-factors

• chaperone proteins

proteins settle on the state that is most ________ ______.

thermodynamically stable

protein state may _____ depending on need.

change

many different types of _____ are found in different parts of the body.

collagen

all types of collagen contain the _____ _____.

triple helix

collagen types are determined by _____ that interrupt the triple helix and their properties, as well as where in the body it is found.

segments

in OI, the degree of severity can depend on the _______ .

type of variant

_______ variant more severe in OI

missense

mechanism of disease by which a variant in one allele can interfere w the function of the normal copy

dominant negative variants

in OI, the _____ _____ in some collagen strands interfered with the normal functioning of the other strands once integrated.

missense variant

complete loss of protein or loss of its normal function

recessive and X-linked disorders

loss of half the amount of protein/half its normal function

haploinsufficiency- dominant disorders

nonsense, whole gene dels, frameshifts, and indels are almost always _______ than missense variants

more deleterious

genetic variants in domains =

higher chance the primary function of the protein is compromised

variants outside domains =

may disrupt overall protein shape or regulatory interactions, which may impede domains from interacting w targets

domains

conserved sequence

by knowing the domain we can predict:

protein function

motifs

recurring tertiary structure of a protein

protein complexes

2+ associated proteins (most biological processes require these)

function of the protein depends on:

multiple layers of structure

the ______ determines the secondary structure, which influences the tertiary structures (domains and motifs)

primary sequence