x-ray crystal structure of the protein  (Brookhaven Instruments)

Journal: The Journal of Biological Chemistry

Article Title: Regulatory ligand binding in plant chalcone isomerase–like (CHIL) proteins

doi: 10.1016/j.jbc.2023.104804

Figure Lengend Snippet: Naringenin and quercetin binding effects on CHIL and CHI proteins. DSF assays of CHI and CHIL–flavanol binding interactions for ( A ) MsCHI-II and naringenin (n = 4), ( B ) PpCHIL-A and naringenin (n = 2), and ( C ) VvCHIL and naringenin (n = 4). Examples of derivative fluorescence data from DSF assays that were used to calculate T m values for ( D ) MsCHI-II and naringenin, ( E ) PpCHIL-A and naringenin, and ( F ) VvCHIL and naringenin. G , DSF assay of VvCHIL with quercetin (n = 4). H , fluorescence enhancement of quercetin in the presence of increasing concentrations of VvCHIL (n = 2), and ( I ) , increasing concentrations of PpCHIL-A (n = 2). Error bars are standard deviations of independent experiments. CHI, chalcone isomerase; CHIL, chalcone isomerase–like protein; DSF, differential scanning fluorimetry; MsCHI-II, type II CHI from Medicago sativa ; PpCHIL-A, CHIL from bryophyte Physcomitrella patens ; VvCHIL, CHIL protein from Vitis vinifera .

Article Snippet: The protein X-ray crystal structure of naringenin bound to type II CHI from Medicago sativa (MsCHI-II) reveals the location and orientation through which naringenin binds to the enzyme active site ( ).

Techniques: Binding Assay, Fluorescence

Journal: The Journal of Biological Chemistry

Article Title: Regulatory ligand binding in plant chalcone isomerase–like (CHIL) proteins

doi: 10.1016/j.jbc.2023.104804

Figure Lengend Snippet: Monomer and oligomer analysis of CHI and CHIL proteins. A , native PAGE ( top ) of PpCHIL-A, VvCHIL, and MsCHI-II. For comparison, the SDS-PAGE gel ( bottom ) shows the same proteins. B , size-exclusion chromatograms of VvCHIL and PpCHIL-A. VvCHIL elutes as two peaks, and PpCHIL-A elutes as a single peak. Inlay : a set of sizing standards used to generate a linear fit and how they compare with the calculated molecular weight values for VvCHIL ( green ) and PpCHIL-A ( magenta ). CHI, chalcone isomerase; CHIL, chalcone isomerase–like protein; MsCHI-II, type II CHI from Medicago sativa ; PpCHIL, CHIL from bryophyte Physcomitrella patens ; VvCHIL, CHIL protein from Vitis vinifera.

Article Snippet: The protein X-ray crystal structure of naringenin bound to type II CHI from Medicago sativa (MsCHI-II) reveals the location and orientation through which naringenin binds to the enzyme active site ( ).

Techniques: Clear Native PAGE, SDS Page, Molecular Weight

Journal: The Journal of Biological Chemistry

Article Title: Regulatory ligand binding in plant chalcone isomerase–like (CHIL) proteins

doi: 10.1016/j.jbc.2023.104804

Figure Lengend Snippet: Structural comparisons of PpCHIL-A and VvCHIL to MtCHI-I bound with naringenin. A , the product-bound structure of MtCHI-I shows naringenin bound and largely buried within the enzyme active site. B , the structure of PpCHIL-A structurally superimposed with MtCHI-I bound to naringenin. The superposition shows that naringenin ( yellow sticks ) fits within a pocket of PpCHIL-A ( magenta ), which is in a similar position to the active site of MtCHI-I. C , the structure of VvCHIL structurally superimposed with MtCHI-I bound to naringenin. The superposition suggests that naringenin ( yellow ) will not fit within the pocket of VvCHIL, which has a different shape than PpCHIL-A because of different amino acids. D , two segments from a multiple sequence alignment of CHIL and CHI amino acid sequences. The MSA contains CHILs from liverwort ( Marchantia polymorpha , MpCHIL), bryophyte ( Physcomitrella patens , PpCHIL-A and PpCHIL-B), lycophyte ( Selaginella moellendorffii , SmCHIL), rice ( Oryza sativa , OsCHIL), grapeseed ( Vitis vinifera , VvCHIL), Arabidopsis thaliana (AtCHIL), Japanese morning glory ( Ipomoea purpurea , IpCHIL), snapdragon ( Antirrhinum majus , AmCHIL), and CHI enzymes from Medicago truncatula (MtCHI-I) and Medicago sativa (MsCHI-II). CHI, chalcone isomerase; CHIL, chalcone isomerase–like protein; MSA, multiple sequence alignment.

Article Snippet: The protein X-ray crystal structure of naringenin bound to type II CHI from Medicago sativa (MsCHI-II) reveals the location and orientation through which naringenin binds to the enzyme active site ( ).

Techniques: Sequencing