Eractions [9]. In order to reveal the mode of binding of two different types of cell wall molecules simultaneously, a ternary complex of CPGRP-S with LPS and SA was crystallized. The structure determination of the complex showed that LPS and SA were observed bound to Site-1 and Site-2 respectively. This indicated the binding potential of CPGRP-S to interact with two independent PAMPs SIS 3 through its two separate binding sites, S-1 and S-2.All India Institute of Medical Sciences, New Delhi, India. The written consent had been given by the donors before blood samples were collected from them.PurificationFresh samples of camel milk were obtained from the National Research Centre on Camels, Bikaner, India. The skimmed milk was diluted twice with 50 mM Tris-HCl pH 8.0. The cation Naringin exchanger CM-sephadex (C-50), pre-equilibrated with 50 mM Tris-HCl pH 8.0 at a concentration of 7 g/l was added to the diluted samples and stirred slowly for 1 hour with a glass rod. The gel was allowed to settle for half an hour after which the solution was decanted. The gel was washed with excess of 50 mM TrisHCl, pH 8.0. It was packed in a column (2562.5 cm) and washed with same buffer until the absorbance reduced to 0.05 at 280 nm. After this, the bound basic proteins were eluted with 0.5 M NaCl in 50 mM Tris-HCl pH 8.0 and desalted by dialyzing it against triple distilled water. The desalted fraction was again passed through a CM-sephadex (C-50) column (1062.5 cm) which was pre-equilibrated with 50 mM Tris-HCl pH 8.0 and eluted with 0.05?.5 M NaCl in the same buffer. The eluted fractions were examined on the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The fractions corresponding to a molecular weight of approximately 20 kDa were pooled. The pooled fractions were concentrated using Amicon ultrafiltration 23977191 cell. The concentrated protein was passed through Sephadex G100 column (10062 cm) using 50 mM Tris-HCl pH 8.0. Two peaks were obtained when the fractions were read at 280 nm wavelength. The purity of the eluted fractions was checked using SDS-PAGE which indicated that the second peak in the gel filtration profile corresponded to the molecular weight of 20 kDa of PGRP-S. The high molecular weight first peak also showed a band at 
about 20 kDa on the SDS-PAGE indicating a polymeric state of CPGRP-S.Materials and Methods Ethics StatementThe peripheral blood was taken from the healthy human volunteers with the approval of the Institute Ethics Committee atTable 1. Data collection and refinement statistics for the structure of the ternary complex of CPGRP-S with LPS and SA.PGRP-S+LPS+SA PDB ID Space group Unit cell dimensions ?a (A) ?b (A) ?c (A) Number of molecules in the asymmetric 
unit ?Vm (A3/Da) Solvent Content ( ) ?Resolution range (A) Number of unique reflections#4 GF9 I89.6 101.9 162.3 4 2.32 47.0 50.0?.8 37206 7.9 (28.9) 33.9 (4.3) 98.8 (99.5) 22.9 26.6 5348 256 48 20 6 0.02 1.9 18.0 11.4 12.7 12.Rsym ( )Binding StudiesFreshly purified sample of CPGRP-S was immobilized on a CM5 carboxyldextran chip using carbodiimide chemistry to a level of 10000 response units (RU) as described previously (9, 10) using a BIAcore-T200 (BIAcore). In one experiment three different concentrations (200 nM, 150 nM, and 100 nM) of analytes, SA and LPS were passed over the immobilized CPGRP-S at a flow rate of 10 ml/min with an injection time of 420 seconds. The regeneration of bound analytes was done using 10 mM NaOH for 100 seconds at a flow rate of 30 ml/min.Eractions [9]. In order to reveal the mode of binding of two different types of cell wall molecules simultaneously, a ternary complex of CPGRP-S with LPS and SA was crystallized. The structure determination of the complex showed that LPS and SA were observed bound to Site-1 and Site-2 respectively. This indicated the binding potential of CPGRP-S to interact with two independent PAMPs through its two separate binding sites, S-1 and S-2.All India Institute of Medical Sciences, New Delhi, India. The written consent had been given by the donors before blood samples were collected from them.PurificationFresh samples of camel milk were obtained from the National Research Centre on Camels, Bikaner, India. The skimmed milk was diluted twice with 50 mM Tris-HCl pH 8.0. The cation exchanger CM-sephadex (C-50), pre-equilibrated with 50 mM Tris-HCl pH 8.0 at a concentration of 7 g/l was added to the diluted samples and stirred slowly for 1 hour with a glass rod. The gel was allowed to settle for half an hour after which the solution was decanted. The gel was washed with excess of 50 mM TrisHCl, pH 8.0. It was packed in a column (2562.5 cm) and washed with same buffer until the absorbance reduced to 0.05 at 280 nm. After this, the bound basic proteins were eluted with 0.5 M NaCl in 50 mM Tris-HCl pH 8.0 and desalted by dialyzing it against triple distilled water. The desalted fraction was again passed through a CM-sephadex (C-50) column (1062.5 cm) which was pre-equilibrated with 50 mM Tris-HCl pH 8.0 and eluted with 0.05?.5 M NaCl in the same buffer. The eluted fractions were examined on the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The fractions corresponding to a molecular weight of approximately 20 kDa were pooled. The pooled fractions were concentrated using Amicon ultrafiltration 23977191 cell. The concentrated protein was passed through Sephadex G100 column (10062 cm) using 50 mM Tris-HCl pH 8.0. Two peaks were obtained when the fractions were read at 280 nm wavelength. The purity of the eluted fractions was checked using SDS-PAGE which indicated that the second peak in the gel filtration profile corresponded to the molecular weight of 20 kDa of PGRP-S. The high molecular weight first peak also showed a band at about 20 kDa on the SDS-PAGE indicating a polymeric state of CPGRP-S.Materials and Methods Ethics StatementThe peripheral blood was taken from the healthy human volunteers with the approval of the Institute Ethics Committee atTable 1. Data collection and refinement statistics for the structure of the ternary complex of CPGRP-S with LPS and SA.PGRP-S+LPS+SA PDB ID Space group Unit cell dimensions ?a (A) ?b (A) ?c (A) Number of molecules in the asymmetric unit ?Vm (A3/Da) Solvent Content ( ) ?Resolution range (A) Number of unique reflections#4 GF9 I89.6 101.9 162.3 4 2.32 47.0 50.0?.8 37206 7.9 (28.9) 33.9 (4.3) 98.8 (99.5) 22.9 26.6 5348 256 48 20 6 0.02 1.9 18.0 11.4 12.7 12.Rsym ( )Binding StudiesFreshly purified sample of CPGRP-S was immobilized on a CM5 carboxyldextran chip using carbodiimide chemistry to a level of 10000 response units (RU) as described previously (9, 10) using a BIAcore-T200 (BIAcore). In one experiment three different concentrations (200 nM, 150 nM, and 100 nM) of analytes, SA and LPS were passed over the immobilized CPGRP-S at a flow rate of 10 ml/min with an injection time of 420 seconds. The regeneration of bound analytes was done using 10 mM NaOH for 100 seconds at a flow rate of 30 ml/min.
