Claims for Patent: 10,001,489

Summary for Patent: 10,001,489

Title:	Method for constructing a novel affinity peptide library for binding immunoglobulin G based on a protein affinity model of protein A
Abstract:	An affinity ligand peptide library of IgG constructed on the basis of Protein A affinity model and the application of a design method thereof. According to the Molecular Mechanics--Poisson-Boltzmann surface area (MM/PBSA) method and on the basis of the known human IgG-Protein A complex structure, the hot spots of Protein A that have high affinity for human IgG are obtained analytically, and a Protein A simplified affinity model is built thereof. An affinity peptide library of IgG is constructed including heptapeptide and octapeptide structural modes. On the basis of the peptide structural modes, the types of inserted amino acids that `X` residues represent are further identified using amino acid location method. Then, molecular docking and molecular dynamics simulation methods are used to screen the candidate peptides successively. Finally, the affinity peptide ligands that can effectively purify IgG are identified using affinity chromatography.
Inventor(s):	Sun; Yan (Tianjin, CN), Zhao; Weiwei (Tianjin, CN), Liu; Fufeng (Tianjin, CN), Shi; Qinghong (Tianjin, CN)
Assignee:	TIANJIN UNIVERSITY (Tianjin, CN)
Application Number:	14/654,731
Patent Claims:	1. A method for constructing a novel affinity ligand peptide library for binding immunoglobulin G on the basis of an affinity model of Protein A, comprising: adding a cysteine to a middle region of a peptide to obtain the following peptides: TABLE-US-00008 FYCHXXXE, FYXHCXXE, FYCHXXR, FYXHCXR, FYXCRXE, YFXCRXE, HXYFCXR, and HXYFCXK; wherein `X` represents the common 19 amino acids except cysteine; and synthesizing one or more of the peptides. 2. The method of claim 1, wherein, the constructing is on the basis of six Staphylococal Protein A hot spots: F132, Y133, H137, E143, R146, and K154. 3. The method of claim 1, further comprising determining the kinds of amino acids `X` in the peptides that are within the scope of the peptide library using an amino acid location method. 4. The method of claim 3, wherein, a candidate peptide library is obtained and shown below: TABLE-US-00009 Peptide & Number of peptides Amino acids `X` represents FYCHX.sub.1X.sub.2X.sub.3E X.sub.1: A, R, N, D, Q, E, H, I, L, K, M, number: 990 T, W, Y, V X.sub.2: A, Q, E, I, L, K X.sub.3: A, R, D, Q, E, L, K, M, P, S, T FYX.sub.1HCX.sub.2X.sub.3E X.sub.1: A, R, N, D, I, P, T, W, Y number: 594 X.sub.2: A, Q, E, I, L, K X.sub.3: A, R, D, Q, E, L, K, M, P, S, T FYCHX.sub.1X.sub.2R X.sub.1: N, D, Q, E, H, I, K, M, F, P, T, number: 112 W, Y, V X.sub.2: Q, E, H, I, K, M, F, W FYX.sub.1HCX.sub.2R X.sub.1: A, R, N, D, I, P, T, W, Y number: 72 X.sub.2: Q, E, H, I, K, M, F, W FYX.sub.1CRX.sub.2E X.sub.1: A, R, N, D, Q, E, G, H, I, L, K, number: 153 M, F, P, W, Y, V X.sub.2: N, D, Q, E, L, M, S, T, W YFX.sub.1CRX.sub.2E X.sub.1: N, D, E, H, I, L, K, M,P, S, T, number: 117 Y, V X.sub.2: N, D, Q, E, L, M, S, T, W HX.sub.1YFCX.sub.2R X.sub.1: A, R, N, D, I, P, T, W, Y number: 54 X.sub.2: Q, H, K, S, W, Y HX.sub.1YFCX.sub.2K X.sub.1: A, R, N, D, I, P, T, W, Y number: 81 X.sub.2: A, R, Q, H, K, F, W, Y, V. 5. The method of claim 4, wherein the peptides in the candidate peptide library are screened by molecular docking, RMSD comparison, and rescreened by molecular dynamics simulation, obtaining peptide ligands possessing high affinity for human immunoglobulin G, which are SEQ ID NO: 1499, FYWHCLDE; SEQ ID NO: 1883, FYFCRWE; SEQ ID NO: 1309, FYIHCLPE; SEQ ID NO: 1576, FYYHCKKE; SEQ ID NO: 859, FYCHWALE; SEQ ID NO: 798, FYCHWQDE; SEQ ID NO: 757, FYCHTIDE; SEQ ID NO: 1073, FYRIICQRE; SEQ ID NO: 397, FYCHHKTE; SEQ ID NO: 606, FYCHLQKE; SEQ ID NO: 122, FYCHRKAE; SEQ ID NO: 147, FYCHNQDE; SEQ ID NO: 82, FYCHRQEE; and SEQ ID NO: 1133, FYNHCASE. 6. The method of claim 2, further comprising determining the kinds of amino acids `X` in the peptides that are within the scope of the peptide library using an amino acid location method. 7. The method of claim 6, wherein, a candidate peptide library is obtained and shown below: TABLE-US-00010 Peptide & Number of peptides Amino acids `X` represents FYCHX.sub.1X.sub.2X.sub.3E X.sub.1: A, R, N, D, Q, E, H, I, L, K, M, number: 990 T, W, Y, V X.sub.2: A, Q, E, I, L, K X.sub.3: A, R, D, Q, E, L, K, M, P, S, T FYX.sub.1HCX.sub.2X.sub.3E X.sub.1: A, R, N, D, I, P, T, W, Y number: 594 X.sub.2: A, Q, E, I, L, K X.sub.3: A, R, D, Q, E, L, K, M, P, S, T FYCHX.sub.1X.sub.2R X.sub.1: N, D, Q, E, H, I, K, M, F, P, T, number: 112 W, Y, V X.sub.2: Q, E, H, I, K, M, F, W FYX.sub.1HCX.sub.2R X.sub.1: A, R, N, D, I, P, T, W, Y number: 72 X.sub.2: Q, E, H, I, K, M, F, W FYX.sub.1CRX.sub.2E X.sub.1: A, R, N, D, Q, E, G, H, I, L, K, number: 153 M, F, P, W, Y, V X.sub.2: N, D, Q, E, L, M, S, T, W YFX.sub.1CRX.sub.2E X.sub.1: N, D, E, H, I, L, K, M,P, S, T, number: 117 Y, V X.sub.2: N, D, Q, E, L, M, S, T, W HX.sub.1YFCX.sub.2R X.sub.1: A, R, N, D, I, P, T, W, Y number: 54 X.sub.2: Q, H, K, S, W, Y HX.sub.1YFCX.sub.2K X.sub.1: A, R, N, D, I, P, T, W, Y number: 81 X.sub.2: A, R, Q, H, K, F, W, Y, V. 8. The method of claim 7, wherein, the peptides in the candidate peptide library are screened by molecular docking, RMSD comparison, and rescreened by molecular dynamics simulation, obtaining the top 14 peptide ligands possessing high affinity for human immunoglobulin G, which are SEQ ID NO: 1499, FYWHCLDE; SEQ ID NO: 1883, FYFCRWE; SEQ ID NO: 1309, FYIHCLPE; SEQ ID NO: 1576, FYYHCKKE; SEQ ID NO: 859, FYCHWALE; SEQ ID NO: 798, FYCHWQDE; SEQ ID NO: 757, FYCHTIDE; SEQ ID NO: 1073, FYRHCQRE; SEQ ID NO: 397, FYCHHKTE; SEQ ID NO: 606, FYCHLQKE; SEQ ID NO: 122, FYCHRKAE; SEQ ID NO: 147, FYCHNQDE; SEQ ID NO: 82, FYCHRQEE; and SEQ ID NO: 1133, FYNHCASE.

Details for Patent 10,001,489

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Csl Behring Ag	CARIMUNE, CARIMUNE NF, PANGLOBULIN, SANDOGLOBULIN	immune globulin intravenous (human)	For Injection	102367	July 27, 2000		2032-12-20
Csl Behring Ag	PRIVIGEN	immune globulin intravenous (human), 10% liquid	Injection	125201	July 26, 2007		2032-12-20
Csl Behring Ag	PRIVIGEN	immune globulin intravenous (human), 10% liquid	Injection	125201	October 02, 2009		2032-12-20