STREPTAVIDIN-CYCLO-AC-[CHPQFC]-NH2, PH 4.8
In crystals of complexes of streptavidin with peptide ligands containing the HPQ sequence the pKa of the peptide histidine is less than 3.0.
Structure-Based Design Tools: Structural and Thermodynamic Comparison with Biotin of a Small Molecule that Binds Streptavidin with Micromolar Affinity
Preparation of a Protein-Dimerizing Ligand by Topochemistry and Structure-Based Design
Topochemical Catalysis Achieved by Structure-Based Ligand Design
Topochemistry for Preparing Ligands that Dimerize Receptors
Binding to Protein Targets of Peptidic Leads Discovered by Phage Display: Crystal Structures of Streptavidin-Bound Linear and Cyclic Peptide Ligands Containing the Hpq Sequence
Structure-Based Design of High Affinity Streptavidin Binding Cyclic Peptide Ligands Containing Thioether Cross-Links
AEAGITGTWYNQLGSTFIVTAGADGALTGTYESAVGNAESRYVLTGRYDSAPATDGSGTALGWTVAWKNNYRNAHSATTW SGQYVGGAEARINTQWLLTSGTTEANAWKSTLVGHDTFTKVKP
SYNTHETIC MOTHER LIQUOR = 75 % SATURATED AMMONIUM SULFATE, 25 % 1.0 M POTASSIUM ACETATE ADJUSTED TO PH 4.8.
THE FOLLOWING ATOMS HAD WEAK DENSITY AND OCCUPANCIES WERE REFINED: 13, 14, 15, MAIN CHAIN OF GLN 24, SIDE CHAIN OF GLN 24, (N, HN, CA, HA OF LEU 25), SIDE CHAIN OF LEU 25, 26, MAIN CHAIN OF ALA 35, SIDE CHAIN OF ALA 35, (MAIN CHAIN AND CB, HB1, HB2 OF ASP 36), (CG, OD1, AND OD2 OF ASP 36), 46, 47, 48, 49, 50, 51, SIDE CHAIN OF SER 52, TERMINUS OF ARG 53, ARG 84 SIDE CHAIN FROM CB OUTWARD, 99, 100, (N AND HN OF 101), (CG, HG1, HG2, CD, OE1, OE2 OF GLU 101), TERMINUS OF ARG 103, (N, HN, CA, HA OF GLU 116), GLU 116 SIDE CHAIN, (N, HN, CA, HA OF 117), (CB, HB1, HB2, HB3 OF 117), (C, O OF 117), LYS 121 FROM CG OUTWARD, LYS 132 SIDE CHAIN, (ACE P 0 AND CYS P 1). RESIDUES 60 - 69 WERE REFINED IN 2 CONFORMATIONS BECAUSE UPON PROTONATION OF ASP 61 AT LOW PH, ASP 61 UNDERGOES A LARGE SHIFT IN CONFORMATION AND CHANGE IN HYDROGEN BONDING. THE LOOP COMPRISING RESIDUES 61 - 69 ALSO UNDERGO CORRESPONDING CONFORMATIONAL CHANGES. HOWEVER SOME OF THESE RESIDUES ARE DISORDERED AND NOT VISIBLE IN EITHER CONFORMATION.
STREPTAVIDIN, PEPTIDE LIGAND CONTAINING HPQ
COMPLEX (BIOTIN-BINDING PROTEIN/PEPTIDE)
COMPLEX (BIOTIN-BINDING PROTEIN-PEPTIDE), CYCLIC PEPTIDE DISCOVERED BY PHAGE DISPLAY, COMPLEX (BIOTIN-BINDING PROTEIN-PEPTIDE) complex
MRKIVVAAIAVSLTTVSITASASADPSKDSKAQVSAAEAGITGTWYNQLGSTFIVTAGADGALTGTYESAVGNAESRYVL TGRYDSAPATDGSGTALGWTVAWKNNYRNAHSATTWSGQYVGGAEARINTQWLLTSGTTEANAWKSTLVGHDTFTKVKPS AASIDAAKKAGVNNGNPLDAVQQ