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Proteins are made by linking amino acids Protein Structure Review and Refinement Introduction Brian Bahnson Dept of Chemistry & Biochemistry, University of Delaware
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Proteins are made by linking amino acids

Feb 25, 2016

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Protein Structure Review and Refinement Introduction. Proteins are made by linking amino acids. Brian Bahnson Dept of Chemistry & Biochemistry, University of Delaware. Several Ways to Visualize Amino Acids. 20 common amino acids . Primary Sequence Secondary Structure. - PowerPoint PPT Presentation
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Page 1: Proteins are made by linking amino acids

Proteins are made by linking amino acids

Protein Structure Review and Refinement IntroductionBrian BahnsonDept of Chemistry & Biochemistry, University of Delaware

Page 2: Proteins are made by linking amino acids

Several Ways to Visualize Amino Acids

Page 3: Proteins are made by linking amino acids

20 common amino acids

Page 4: Proteins are made by linking amino acids

NC N

C NC N

C NC N

C NC N

C

H O

H O

H O

H O

H O

H O

H O

HO R R R R

R R R R

N

C NC N

C N C

O

H O

H O

H

OH

C

O

NN-term

H

NCN

CNCN

C

O

HO

HO

H

HC

O

N

C-term

O

R

R R

R R

R R

RR

R

H

N

C NC N

C

O

H O

H OH

C

O

NN-term

H

R R

R R

NC C-term

OH

R

N

C NC N

C

O

H O

H OH

C

O

NN-term

H

R R

R R

NC C-term

OH

R

-helix

anti-parallel -sheet

parallel -sheet

double headed arrows indicate hydrogen bonds

Primary Sequence Secondary Structure

Page 5: Proteins are made by linking amino acids

Secondary Structure Tertiary Structure

Page 6: Proteins are made by linking amino acids

Tertiary Structure Quaternary Structure

Alcohol dehydrogenase is a homotetramer

Page 7: Proteins are made by linking amino acids

The Peptide Plane

Page 8: Proteins are made by linking amino acids

Peptide Plane Reduces the Number of Parameters

Tortion angles

PHI

PSI

Page 9: Proteins are made by linking amino acids

Ramachandran Plot to Evaluate Outliers of “Good Protein Geometry”

Ramachandran plotfrom htADH

 

core (%) 91.3 %

allowed (%) 8.2 %

generously allowed 0.4 %

disallowed none

Page 10: Proteins are made by linking amino acids

Macromolecular Protein Crystallography

Page 11: Proteins are made by linking amino acids

Experimental Data Points vs. Refined Parameters

X-ray Diffraction ReflectionsExperimental Data Points Electron Density Map and

Refined Model of Enzyme

Page 12: Proteins are made by linking amino acids

RMSD from Ideal Protein Geometry

RMSD from ideal geometryfor htADH structure  

bonds (Å) 0.007

angles (°) 1.30

dihedrals (°) 23.60

impropers (°) 0.85

Page 13: Proteins are made by linking amino acids

Least Squares Refinement Summed Over all Atoms and Data Points

From Crystallography Made Crystal Clear

Page 14: Proteins are made by linking amino acids

Molecular Dynamic Simulation of a designed mini-protein (Trp-cage)

From the Duan labhttp://www.duanlab.ucdavis.edu/

The movie shown2 slides ahead is 69.5 MBand can be downloaded here

Page 15: Proteins are made by linking amino acids

H3NN

NN

NN

NN

NN

NN

NN

NN N

NN N

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

OH

H

H

H

H

H

H

H

H

H H

H

H

H

H

H

H

HH H

H

O

H2N

HO

O

NH2

NH

N1

L2

Y3

I4

Q5

W6

L7

+H3N

O-O

OH

OH

K8

D9

G10

G11

P12

S13

S14

Trp Cage Peptide Sequence

1 5 10 15 20N L Y I Q W L K D G G P S S G R P P P S

HN

+H2NNH2

OH

S20

G15

R16

P17

P18

P19

Hydrogen Bonding Connection

L2:O W6:HY3:O L7:HI4:O K8:H

G10:O S13:HG11:O S14:H

W6:HE1 R16:O

L7:O G10:HW6:O G11:H

Page 16: Proteins are made by linking amino acids