6A6V

Crystal structure of the modified fructosyl peptide oxidase from Aspergillus nidulans with 7 additional mutations, in complex with FSA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.90 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.168 

Starting Model: experimental
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This is version 2.1 of the entry. See complete history


Literature

Creation of haemoglobin A1c direct oxidase from fructosyl peptide oxidase by combined structure-based site specific mutagenesis and random mutagenesis.

Ogawa, N.Kimura, T.Umehara, F.Katayama, Y.Nagai, G.Suzuki, K.Aisaka, K.Maruyama, Y.Itoh, T.Hashimoto, W.Murata, K.Ichimura, M.

(2019) Sci Rep 9: 942-942

  • DOI: https://doi.org/10.1038/s41598-018-37806-x
  • Primary Citation of Related Structures:  
    6A6R, 6A6S, 6A6T, 6A6U, 6A6V

  • PubMed Abstract: 

    The currently available haemoglobin A1c (HbA1c) enzymatic assay consists of two specific steps: proteolysis of HbA1c and oxidation of the liberated fructosyl peptide by fructosyl peptide oxidase (FPOX). To develop a more convenient and high throughput assay, we devised novel protease-free assay system employing modified FPOX with HbA1c oxidation activity, namely HbA1c direct oxidase (HbA1cOX). AnFPOX-15, a modified FPOX from Aspergillus nidulans, was selected for conversion to HbA1cOX. As deduced from the crystal structure of AnFPOX-15, R61 was expected to obstruct the entrance of bulky substrates. An R61G mutant was thus constructed to open the gate at the active site. The prepared mutant exhibited significant reactivity for fructosyl hexapeptide (F-6P, N-terminal amino acids of HbA1c), and its crystal structure revealed a wider gate observed for AnFPOX-15. To improve the reactivity for F-6P, several mutagenesis approaches were performed. The ultimately generated AnFPOX-47 exhibited the highest F-6P reactivity and possessed HbA1c oxidation activity. HbA1c levels in blood samples as measured using the direct assay system using AnFPOX-47 were highly correlated with the levels measured using the conventional HPLC method. In this study, FPOX was successfully converted to HbA1cOX, which could represent a novel in vitro diagnostic modality for diabetes mellitus.


  • Organizational Affiliation

    Research Laboratories, Kyowa Medex Co., Ltd., 600-1, Minami-ishiki, Nagaizumi-cho, Sunto-gun, Shizuoka, 411-0932, Japan. noriyuki.ogawa@kyowa-kirin.co.jp.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Fructosyl amine: oxygen oxidoreductaseA,
B [auth H]
438Aspergillus nidulansMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.90 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.168 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 135.54α = 90
b = 135.54β = 90
c = 144.68γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-05-15
    Type: Initial release
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations
  • Version 2.1: 2023-11-22
    Changes: Data collection, Database references, Refinement description, Structure summary