Electrostatic Potential onHLA-DPB1*1701 and HLA-

DPB1*0401:Implications for Putative

Mechanism of Chronic Beryllium Disease

Health Effects Laboratory Division,

National Institute for Occupational Safety and Health,

Morgantown, WV

James A. Snyder, Ainsley Weston, Sally S. Tinkle and Eugene Demchuk

Objective

to understand the physical-chemical reasons for beryllium toxicity

in Chronic Beryllium Disease (CBD)

Periodic TableWhat makes Be toxic?

The Test Hypothesis

Be2+ binds to HLA-DP and changes the specificity of molecular recognition

Goal: To identify and test the Be2+ binding mode

Experimental Evidence

• Amicosante, M., Sanarico, N. Berretta, F., Arroyo, J., Lombardi, G., Lechler, R., Colizzi, V. and Saltini, C. Beryllium Binding to HLA-DP Molecule Carrying the Marker of Susceptibility to Berylliosis Glutamate 69. Human Immunology, 62, 686-693 (2001)

• Fontenot, A.P., Torres, M., Marshall, W.H., Newman, L.S. and Kotzin, B.L. Beryllium Presentation to CD4+ T Cells Underlies Disease-Susceptibility HLA-DP Alleles in Chronic Beryllium Disease. Proc. Natl. Acad. Sci. USA, 97, 12717-12722 (2000)

MHC class II

cellmembrane

Crystal Structure of Human Class II MHC Proteins

in the Protein Data Bank (PDB)HLA-DR1

• 1AQD HLA-DR1 (DRA, DRB1 0101) Human MHC Class II complexed with endogenous peptide• 1DLH HLA-DR1 (DRA, DRB1 0101) Human Class II histocompatibility protein (extracellular domain)• 1FYT HLA-DR1, DRB1 0101• 1HQR DRA*0101 + DRB5*0101• 1KG0 the Epstein-Barr virus Gp42 Protein bound to the MHC Class II HLA-DR1• 1SEB complex of the Human MHC Class II Glycoprotein HLA-DR1 and the bacterial superantigen SEB

HLA-DR2• 1BX2 HLA-DR2 (DRA*0101, DRB1*1501) complexed with a peptide from Human myelin basic protein

1FV1 immunodominant peptide from myelin basic protein in different registers by two HLA-DR2 allelesHLA-DR3

• 1A6A clip bound to HLA-DR3HLA-DR4

• 1D5M HLA-DR4 complexed with peptide and SEB• 1D5X HLA-DR4 complexed with dipeptide mimetic and SEB• 1D5Z HLA-DR4 complexed with peptidomimetic and SEB• 1D6E HLA-DR4 complex with peptidomimetic and SEB• 1J8H HLA-DR1, DRA + HLA-DR4, DRB1*0401• 2SEB HLA-DR4 complexed with a peptide from Human collagen II

HLA-DQ8• 1JK8 Human insulin peptide-HLA-DQ8 complex

HLA-DM• 1HDM histocompatibility antigen HLA-DM

of HLA-DPB1*1701 with chain of HLA-DR2 (PDB: 1FV1B) 10 20 30 40 *1701 RATPENYVHQLRQECYAFNGTQR - - FLERYIYNREEFVRFDS 1FV1 GDTRPRFLQQDKYECHFFNGTERVRFLHRDIYNQEEDLRFDS 10 20 30 40 50 60 70 80 *1701 DVGE FRAVTELGRPDEDYWNSQKDI LEEERAVPDRMCRHN 1FV1 DVGEYRAVTELGRPDAEYWNSQKDFLEDRRAAVDTYCRHN 50 60 70 80 90 100 110 120 *1701 YELDEAVTLQRRVQPKVNVSPSKKGPLQHHNLLVCHVTDF 1FV1 YGVGESFTVQRRVEPKVTVYPARTQTLQHHNLLVCSVNGF 90 100 110 120 130 140 150 160 *1701 YPGSIQVRWFLNGQEET AGVVSTNLIRNGDWTFQ ILVMLE 1FV1 YPGSIEVRWFRNS QEEKAGVVSTGLIQNGDWTFQTLVMLE 130 140 150 160 170 180 190 200 *1701 MTPQQGDVY ICQVEHTSLDSPVTVEWKAQSDSAQSKTLTG 1FV1 TVP RS GEVYTCQVEHPSVTSPLTVEWRA 170 180 190

Sequence Alignment

Molecular Dynamics…

of -carbon atom coordinates relative to starting (crystallographic) positionsat 1 Pico-second intervals

Total Deviation

Total Chargeon HLA-DP proteins

DR Template Protein: -14

HLA-DPA1*01031/B1*0401: -17/-3

HLA-DPA1*01031/B1*1701: -17/-9

Be2+

CBD Susceptibility Odds and the Charge on -chain of

HLA-DP HLA-DPB1 Odds Charge

*1701 -9

*0601 -9

*0901, *1001 -9, -9

*1901 -8

*0201 -7

*0401 -3

1 40

*1701 RATPENYVHQ LRQECYAFNG TQRFLERYIY NREEFVRFDS *0401 RATPENY LFQGRQECYAFNG TQRFLERYIY NREEFARFDS

41 -1-1 -2 80 *1701 DVGEFRAVTE LGRPDEDYWN SQKDILEEERAVPDRMCRHN *0401 DVGEFRAVTE LGRPAAEYWN SQKDILEEKRAVPDRMCRHN

81 -1-1 120 *1701 YELDEA VTLQRRVQPKVNVS PSKKGPLQHH NLLVCHVTDF *0401 YELGGPMTLQRRVQPRVNVS PSKKGPLQHH NLLVCHVTDF

121 160 *1701 YPGSIQVRWF LNGQEETAGV VSTNLIRNGD WTFQILVMLE *0401 YPGSIQVRWF LNGQEETAGV VSTNLIRNGD WTFQILVMLE

161 188 *1701 MTPQQGDVY I CQVEHTSLDS PVTVEWKA *0401 MTPQQGDVYT CQVEHTSLDS PVTVEWKA

Sequence Alignment of HLA-DPB1*1701 with HLA-DPB1*0401

-chain

Class II MHC antigen-binding Pocket

-chain

Poisson-Boltzmann Equation

Finite Difference PB Methods

  

S V V

ε dS εk dV ρdV

V V V

ε dS εk dV ρdV

using divergence theorem:

6

2 3 2

1i j i j S i

j

q h ε h ε I

HLA-DPA1*01031/B1*0401 (model)

Electrostatic Potential Surface

Map

HLA-DPA1*01031/B1*1701 (model)

Electrostatic Potential Surface

Map

*1701 MEP Movie

*0401 MEP Movie

1701 MEP Movie

Conclusion

Our results are consistent with the hypothesis that glutamic acid at position 69 of the -chain of HLA-DP may be a determinant of susceptibility to Chronic Beryllium Disease

James A. Snyder

Eugene Demchuk

Ainsley Weston genetics

Sally S. Tinkle immunology

People

Health Effects Laboratory Division,

National Institute for Occupational Safety and Health,

Morgantown, WV

computational studies

Future Goal: To model interactions of Be2+ with

HLA-DP proteins