University homepage Suomeksi På svenska In English
University of Helsinki Institute of Biotechnology
Biomolecular NMR & Protein Engineering

Group Leader

Dr. Hideo Iwai

Tel: +358-02941 59752
E-mail: hideo -dot- iwai
-at- helsinki -dot- fi

Institute of Biotechnology
Street address: Viikinkaari 1 (P.O.Box 65)
00014 University of Helsinki
Tel: +358-2941
fax +358-2941 5 9541

Business Identity Code:
(University of Helsinki)

Telephone directory (all contact information included)

E-mail directory

How to get here
(Helsinki city map)

Publications from Dr. Hideo Iwai

Here for PubMed. ,# equal contribution. * corresponding author, Click each for PDF version.

52. Mikula, K.M., Tascón, I., Tommila, J.J., & Iwaï. H.* (2017) Segmental isotopic labeling of a single-domain globular protein without any refolding step by an asparaginyl endopeptidase. accepted.
51. Aranko, A.S., & Iwaï, H. (2017) Protein ligation by HINT domains. in Chemical Ligation: Tools for Biomolecule Synthesis and Modification (Wiley). 421-445.
50. Ciragan, A., Aranko, A.S., Tascon, I. & Iwaï, H. (2016) Salt-inducible protein splicing in cis and trans by inteins from extremely halophilic archaea as a novel protein-engineering tool. J. Mol. Biol 428, 4573-4588.
49. Guerrero, F., Ciragan, A. & Iwaï, H. (2015) Tandem SUMO fusion vectors for improving soluble protein expression and purification. Protein Expr. Purif. , 116, 42–49. Plasmids
48. Vegh, R.B., Bloch, D.A., Bommarius, A.S., Verkhovsky, M., Pletnev,S., Iwaï, H., Bochenkova, A.V., & Solntsev, K.M. (2015) Hidden Photoinduced Reactivity of the Blue Fluorescent Protein mKalama1. Phys. Chem. Chem. Phys., 17(19):12472-85.
47. Aranko, A.S., Wlodawer, A., & Iwaï H.* (2014) Nature’s recipe for splitting inteins. Protein Eng. Des. Sel. 27(8), 263–271.
46. Aranko, A.S., Oeemig, J.S., Zhou, D., Kajander, T., Wlodawer, A., & Iwaï H.* (2014) Structure-based engineering and comparison of novel split inteins for protein ligation. Mol. Biosyst. 10 (5), 1023 - 1034 (HOT articles) Suppl. Plasmids
45. Aranko, A.S., Oeemig, J.S., Kajander, T., & Iwaï H.* (2013) Intermolecular domain swapping induces intein-mediated protein alternative splicing. Nature Chemical Biology 9, 616–622 Suppl. EDITORS' CHOICE in Science Plasmids
44.Bhattacharjee, A., Oeemig,J.S., Kolodziejczyk, R., Meri,T,. Kajander, T., Iwaï,H., Jokiranta, T.S. and Goldman, A. (2013) Structural basis for complement evasion by Lyme disease pathogen Borrelia burgdorferi. J. Biol. Chem. 288, 18685-95
43. Aranko, A.S., Oeemig, J.S., & Iwaï, H.* (2013) Structural basis for protein trans-splicing by a Bacterial Intein-Like domain: protein ligation without nucleophilic side-chains. FEBS J. 280, 3256-69.
42. Repo, H., Oeemig, J.S., Djupsjöbacka, J., Iwaï, H.* and Heikinheimo P.* (2012) A Monomeric TIM-barrel Structure from Pyrococcus furiosus is Optimised for Extreme Temperatures.Acta Cryst. D68, 1479–1487.
41. Minato,Y., Ueda,T., Shimada, I., and Iwaï, H.* (2012) Segmental isotopic labeling of a 140 kD dimeric multi-domain protein CheA from Escherichia Coli by Expressed Protein Ligation and Protein Trans-Splicing. J. Biomol. NMR, 53,191-207. 
40. Oeemig, J.S., Zhou, D., Kajander, T., Wlodawer, A., & Iwaï, H.* (2012) NMR and crystal structures of the Pyrococcus horikoshii RadA intein guide a strategy for engineering a highly efficient and promiscuous intein. J. Mol. Biol. 412, 85-99
39. Ellilä, S, Jurvansuu, J.M. and Iwaï, H. * (2011) Evaluation and comparison of protein splicing by exogenous inteins with foreign exteins in Escherichia coli. FEBS lett. 585, 3471-3477.
38. DiMaio, F., Terwilliger, T.C., Read, R.J., Wlodawer, A., Oberdorfer, G., Wagner, U., Valkov, E., Alon, A., Fass, D., Axelrod, H.L., Das, D., Vorobiev, S.M., Iwaï, H., Pokkuluri, P.R., and Baker, D. (2011) Improved molecular replacement by density- and energy-guided protein structure optimization. Nature 473, 540–543. evaluated by F1000
37. Lyskowski, A.,# Oeemig, J.S.,# Jaakkonen, A., Rommi, K., DiMaio, F., Zhou, D., Kajander, T., Baker, D., Wlodawer, A., Goldman, A. and Iwaï, H.* (2011) Cloning, expression, purification, crystallization and preliminary X-ray diffraction data of Pyrococcus horikoshii RadA intein. Acta Crystallogr. F-Struct. Biol. Cryst. Commun. F67, 623–626
36. Anttila, J., Heinonen, P., Nenonen, T., Pino, A., Iwaï, H., Kauppi, E., Soliymani, R., Baumann, M., Saksi, J., Suni, N. and Haltia, T. (2011) Is coproporphyrin III a copper-acquisition compound in Paracoccus denitrificans ? Biochim Biophys Acta 1807, 311-8.
35. Volkmann, G. and Iwaï, H.* (2010) Protein trans-splicing and its use in structural biology: opportunities and limitations. Mol. Biosyst. 6, 2110-2121.
34. Buchinger, E., Aachmann, F.L, Aranko, A.S., Valla, S.,Sjåk-Bræk, G., Iwaï, H. and Wimmer, R. (2010) Use of Protein trans-splicing to produce active and segmentally 2H, 15N labelled mannuronan C5-epimerase AlgE4. Prot. Sci. 19, 1534-1543.
33. Muona, M., Aranko, A.S., Raulinaitis, V. and Iwaï, H.* (2010) Segmental isotopic labelling of multi-domain and fusion proteins by protein trans-splicing in vivo and in vitro. Nature Protocol 5, 574 - 587. evaluated by Faculty1000
32. Busche, A.E.L.,# Aranko, A.S.,# Talebzadeh-Farooji, M., Bernhard, F., Dötsch, V., and Iwaï,H.* (2009) Segmental isotopic labelling of a central domain in a multi-domain protein by protein trans-splicing using only one robust DnaE intein. Angew. Chem. Int. Edit. 48, 6128 –6131.. evaluated by Faculty1000 (Supporting info).
31. Oeemig, J.S.# Aranko,A. S.,# Djupsjöbacka, J., Heinämäki, K., and Iwaï H.* (2009) Solution structure of DnaE intein from Nostoc punctiforme: Structural basis for the design of a new split intein suitable for site-specific chemical modification. FEBS lett. 583 1451-1456. 2010 FEBS lett. Young Group Leader Award
30. Aranko, A.S., Züger,S., Buchinger, E., and Iwaï, H.* (2009) In vivo and in vitro protein ligation by naturally occurring and engineered split DnaE inteins. PLoS ONE 4(4): e5185.
29. Heinämäki, K.,# Oeemig, J.S.,# Pääkkonen, K., Djupsjöbacka, J., and Iwaï, H.* (2009) NMR resonance assignment of DnaE intein from Nostoc punctiforme. Biomol. NMR Assign. 3 41-43. Published online
28. Iwai, H., Aranko, A.S. and Djupsjöbacka, J. (2008) Protein ligation using protein trans-splicing.J Pept Sci. 14, 183-183 Suppl. S
27. Muona, M. Aranko, A.S. and Iwai, H.* (2008) Segmental isotopic labelling of a multi-domain protein by protein ligation using protein trans-splicing. ChemBioChem 9, 2958-2961 (supporting info)

26. Iwai, H.* and Züger, S. (2007) Protein ligation: applications in NMR studies of proteins Biotechnol Genet Eng Rev. 24, 129-146
25. Iwai, H.* and Fiaux, J (2007)
Use of biosynthetic fractional 13C-labeling for backbone NMR assignment of proteins
J. Biomol. NMR, 37, 187-193 
24. Iwai, H.*, Züger, S., Jin J., and Tam, P.H. (2006)
Highly efficient protein trans-splicing by a naturally split DnaE intein from Nostoc punctiforme.
FEBS lett. 580, 1853-1858.   Suppl.
23. Züger, S. and  Iwai, H.* (2005)
Intein-based biosynthetic incorporation of unlabeld protein tags into isotopically labeled proteins for NMR studies. Nature Biotechnology. 23, 736-740.  Suppl. [News 1, 2]
22. Iwai, H.*, Forrer, P., Plückthun, A. and Güntert, P. (2005)
NMR solution structure of the monomeric form of the bacteriophage lambda capsid stabilizing protein gpD.
J. Biomol. NMR. 31, 351-6
21. Pervushin, K., Wider, G., Iwai H. and Wüthrich K. (2004)
NMR structures of salt-refolded forms of the 434-repressor DNA-binding domain in 6 M urea.
Biochemistry 43,13937-43

20. Iwai, H., Wider, G. and Wüthrich, K. (2004)
NMR structure of a variant 434 repressor DNA-binding domain devoid of hydroxyl groups.
J. Biomol. NMR. 29, 395-8.
19. Takeuchi, K, Takahashi, H., Sugai, M, Iwai, H., Kohno, T., Sekimizu, K., Natori, S., and Shimada, I. (2004)
Channel forming membrane permeabilization by an antibacterial protein: Sapecin; determination of membrane-buried and oligomerization surfaces by NMR.
J. Biol. Chem. 279, 4981-4987
18. Iwai, H.*, Forrer, P., Plückthun, A. and Güntert, P. (2004)
Assignments of 1H and 15N resonances of the bacteriophage lambda capsid stabilizing protein gpD.
J. Biomol. NMR. 28, 89-90


17. Hofmann, A., Iwai, H., Hess, S., Plückthun, A. and Wlodawer, A. (2002)
Crystal structure of cyclized green fluorescent protein.
Acta Crystallographica. D 58, 1400-6
16. Patzelt, H., Goto, N., Iwai, H., Lundstrøm, K.and Fernholz E. (2002)
Modern methods for isotope labelling of proteins
in BioNMR Techniques in drug research (Wiley-VCH).
15. Iwai, H. and Plückthun A. (2002)
Effects of backbone cyclization on protein stability and folding.
Nova Acta Leopoldina suppl. 16 135-136.
14. Iwai, H., Lingel, A. and Plückthun A. (2001)
Cyclic green fluorescent protein produced in vivo using an artificially split PI-PfuI intein from Pyrococcus furiosus.
J. Biol. Chem. 276, 16548-54.
13. Mössner, E. Iwai, H. and Glockshuber, R. (2000)
Influence of the pKa value of the buried, active-site cysteine on the redox properties of thioredoxin-like oxidoreductases
FEBS lett. 477, 21-26
12. Iwai, H. and Plückthun, A. (1999)
Circular β-lactamase: stability enhancement by cyclizing the backbone.
FEBS lett. 459, 166-172.
11. Fernandez, C., Szyperski, T., Billeter, M., Ono, A., Iwai, H., Kainosho, M. and Wüthrich, K. (1999)
Conformational Changes of the BS2 Operator DNA upon Complex Formation with the Antennapedia Homeodomain Studied by NMR with 13C/15N-labeled DNA.
J. Mol. Biol. 292, 609-617.
10. Iwai, H. (1998)
Expression, stabilities, and NMR studies of hydration of recombinant variants of the DNA binding domain of phage 434 repressor.
Diss. ETH Nr. 12684
9. Fernandez, C., Szyperski, T., Ono, A., Iwai, H., Tate, S., Kainosho, M. and Wüthrich, K. (1998)
NMR with 13C, 15N-doubly-labeled DNA: the Antennapedia homeodomain complex with a 14-mer DNA duplex.
J. Biomol. NMR 12, 25-37
8. Sobol, A.G., Wider, G., Iwai, H. and Wüthrich, K. (1998)
Solvent magnetization artifacts in high-field NMR studies of macromolecular hydration.
J. Magn. Reson. 130, 262-271
7. Szyperski, T., Ono, A., Fernandez, C., Iwai, H., Tate, S., Wüthrich, K. and Kainosho, M. (1997)
Measurement of 3Jc2'p scalar couplings in a 17kDa protein complex with 15N/13C labelled DNA distinguishes the BI and BII phosphate conformations of the DNA.
J. Am. Chem. Soc. 119, 9901-9902.
6. Pellecchia, M., Wider, G., Iwai, H. and Wüthrich, K. (1997)
Arginine side chain assignments in uniformly 15N-labeled proteins using the novel 2D HE(NE)HGHH experiment.
J. Biomol. NMR 10, 193-197.
5. Lüginbuhl, P., Pervushin, K.V., Iwai, H. and Wüthrich, K. (1997)
Anisotropic molecular rotational diffusion in 15N spin relaxation studies of protein mobility.
Biochemistry 36, 7305-7312.
4. Pellecchia, M., Iwai, H., Szyperski, T. and Wüthrich, K. (1997)
The 2D NMR experiments H(C)CO2 and HCCO2 for assignment and pH-titration of carboxylate groups in uniformly 15N/13C labelled proteins.
J. Magn. Reson. 124, 274-278.
3. Kim, J.I., Konishi, S., Iwai, H., Kohno, T., Gouda, H., Sato, K., Shimada, I. and Arata, Y. (1995)
Three-dimensional solution structure of the calcium channel antagonist omega-agatoxin IVA: consensus molecular folding of calcium channel blockers.
J. Mol. Biol. 250, 659-671.

2. Kim, J.I., Iwai, H., Kurata S., Takahashi M., Masuda K., Shimada I., Natori S., Arata Y. and Sato K. (1994)
Synthesis and characterization of sapecin and sapecin B
FEBS Lett. 342, 189-92.

1. Iwai, H., Nakajima, Y., Natori, S., Arata, Y. and Shimada, I. (1993)
Solution conformation of an antibacterial peptide, sarcotoxin IA, as determined by 1H-NMR.
Eur. J. Biochem. 217, 639-44.

Presentation. (I:invited)

H.Iwai (2017) Segmental isotopic labeling of proteins. Advanced Isotopic Labelling Methods for Integrated Structural Biology, March. 10–13, 2017, Grenoble, France..
H.Iwai (2016) Protein ligation for protein NMR and beyond. Swedish NMR Centre 25 year anniversary symposium. Oct. 13. 2016. Göthenburg, Sweden.
H.Iwai (2016) Protein Engineering of HINT domains for Protein Ligation. EMBO conference: The biochemistry and chemistry of biocatalysis: From understanding to design. 12/06/2016 -15/06/2016 Oulu, Finland
H.Iwai (2015) Protein Splicing and related phenomena: Tools for Protein NMR. NMR symposium, 10th December, 2015. Trondheim, Norway.
H.Iwai (2014 ) Inteins. Symposium Biomolecular NMR Spectroscopy. 10-11 Nov 2014, Biozentrum, Basel. Switzerland.
H.Iwai (2013) Structure-guided protein design towards segmental isotopic labeling of globular, multi-domain, and membrane proteins. 3rd BioNMR Annual User Meeting: NMR and protein dynamics in structural biology. Hotel Benczur, Budapest, Hungary. June. 10–13, 2013.
H.Iwai (2012) Backbone cyclization by novel split protein-splicing domains: lessons from Kalata B1. Heron Island, Australia. Oct. 15–17, 2012. (I)
H.Iwai (2012) Recent advancement in segmental isotopic labeling of multi-domain proteins. the XXVth International Conference on Magnetic Resonance in Biological System. Cité center de congrés, Lyon, France. Aug. 19–24, 2012.

H.Iwai (2011) Stable Isotopic Labeling of Proteins for Biomolecular NMR in Post-structural Genomics Era. The international ISNMR2011, the 50th Memorial Annual Meeting of the NMR Society of Japan. . Yokohama, Japan. Nov. 15–18, 2011. (I)

H.Iwai (2010) Protein and peptide ligation by split inteins. 5th International Peptide Symposium. Kyoto International Conference Center. Kyoto, Japan. December 4–9, 2010.

H.Iwai (2010) Protein splicing in cis and trans: a versatile tool for structural biology and post-translational modulation of protein functions. 35th FEBS Congress, Götenborg, Sweden. June 26-July 1, 2010 (I: FEBS lett. young group leader Lecture)
H.Iwai (2009) Protein trans-splicing as an enabling tool in structural
biology. The VIII European Symposium of the Protein Society, Kongresshaus, Zürich, Switzerland, June 24-25, 2009 (I)
H.Iwai (2008) Segmental isotope-labeling using in vivo and in vitro protein trans-splicing: How to make it work. NMR-Life Workshop BNMRZ "Protein expression and isotope labeling for structural biology", München, Germany, July 24-25, 2008 (I)
H.Iwai (2006) Intein-based protein engineering. The 89th CSC conference, Halifax, NS, Canada, 27-31. May, 2006 (I)
H.Iwai (2006) Intein-based protein engineering for NMR studies. The 27th Danish NMR Discussion Meeting, Rebuild, Denmark. 9-10. Jan, 2006 (I)
Iwai, H. (2004) Exploring protein splicing, Biochemistry seminar, University of Saskatchewan, 29th Sep 2004, Saskatoon, Canada
Iwai, H (2003) Application of protein splicing domains. Department of Pharmaceutical Science,Toyama Medical and Pharmaceutical University, 29th September 2003, Toyama,
Japan (I)
Iwai, H (2002) Protein NMR Spectroscopy Combined with Protein Engineering Approaches'”, Department of chemistry, University of Saskatchewan, 31st October 2002, Saskatoon, Canada (I)
Iwai, H. (2002) Protein NMR spectroscopy combined with protein engineering approaches. Nestle Research Institute, Oct 24 2002, Lausanne Switzerland (I)
Iwai, H. (2002) Intein-based protein engineering for protein NMR spectroscopy. Max-Plank-Institute, 24th September,2002, Göttingen, Germany
Iwai, H. (2002) Protein NMR spectroscopy combined with protein engineering approaches. Salk Institute, March 1,2002,San Diego, USA
Iwai, H. (2002) Protein NMR spectroscopy combined with protein engineering approaches. Universitaet Leipzig, 28 January, 2002, Leipzig, Germany
Iwai, H., and Plückthun, A. (2000) Effects of backbone cyclization on protein stability and folding. Leopoldina-Symposium "Structure, Self-organization and Stability of Proteins: Experiments and Models" 21. - 23. September, Wittenberg, Germany
Iwai, H (2000) NMR Spectroscopy and Protein Engineering: from Hydration to Cyclic Protein. Novartis Pharma, June 16, 2000, Basel, Switzerland


J. S. Oeemig, A. S., Aranko, and H. Iwai (2010) DnaE Intein Structure from Nostoc punctiforme and Design of New Split Inteins. Euromar 2010, 17th ISMAR Conference, Florence, Italy, July 4-9, 2010.
J. S. Oeemig and H. Iwai (2009) NMR Solution Structure of DnaE Intein from Nostoc
punctiforme. June 14-18. The VIII European Symposium of the Protein Society, Kongresshaus, Zürich, Switzerland
A. E. L. Busche, C. Hein, A. Koglin, F. Löhr, C. T. Walsh, H. Iwai, and V. Doetsch (2009) Segmental isotopic labeling as a tool to solve the structure of three consecutive ACP domains in the Curacin A synthetase. June 14-18. The VIII European Symposium of the Protein Society, Kongresshaus, Zürich, Switzerland.
A.S. Aranko and H. Iwai (2009) How to make protein ligation by protein trans-splicing work
, June 14-18. The VIII European Symposium of the Protein Society, Kongresshaus, Zürich, Switzerland.
E. Buchinger, F. Aachmann, H. Iwai, R. Wimmer (2009) Segmental labelled AlgE4- an alginate epimerase. The VIII European Symposium of the Protein Society, Kongresshaus, Zürich, June 14-18, Switzerland.
H. Iwai, A. S. Aranko J. Djupsjöbacka (2008) Protein ligation using protein trans-splicing. 30th European Peptide Symposium. 31 Aug.-5. Sept. 2008, Helsinki, Finland.
J. Djupsjöbacka, M. Muona, A. S. Aranko. and H. Iwai (2008) Protein ligation using protein-trans splicing: toward segmental isotope-labelling of multi-domain proteins for NMR studies. INPEC meeting 2008, June 12 - 15, Naantali, Finland (the best poster award)
A. S. Aranko and H. Iwai (2008) Site-specific labelling of proteins using an engineered intein (2008) INPEC meeting 2008, June 12 - 15, Naantali, Finland.
K. Pääkkonen, J. Fiaux, and H. Iwai,(2007) ISMAR2007 Optimization of stable-isotope labeling for backbone resonance assignment of proteins, Kenting, Taiwan.
Pääkkonen, K. Iwai, H, (2007) Protein backbone resonance assignment from fractional 13C-labeling data. EUROMAR 2007, 1-6, July. Tarragona , Spain.
Iwai, H, Mahlakõiv, T., Karjalainen, K. Knuuti, J. (2006) In vivo segmental isotope labeling using trans-splicing. XXIInd ICMRBS 2006, 20-25. Aug. Göttingen, Germany.
Iwai, H, Züger, S (2005) New approach to improve protein stability and solubility for NMR studies. VIth European Symposium of the Protein Society,30 Apr-4. May, Barcelona, Spain.
Züger, S., Iwai, H. (2005) New approach to improve protein stability and solubility for NMR studies. Keystone Symposia, Frontiers of NMR in Molecular Biology IX. 29. Jan-04 Feb., Banff, Alberta, Canada.
Iwai, H., Lingel, A., Taguchi, H. and Plückthun, A. (2001) Circular proteins: stability enhancemen by backbone cyclization. Spetsai Summer School 2001, Protein Biology: From Synthesis to Function and Disease. 4-14 September, Island of Spetses, Greece
Iwai, H., Zerbe, O. and Plückthun, A. (2000) Effects of the Backbone Cyclization on Protein Stability and Folding as Characterized by NMR spectroscopy. XIX International Conference on Magnetic Resonance in Biological Systems. August 20-25, 2000, Convention Center - Florence, Italy.
Iwai, H., and Plückthun, A. (1999) Circular protein: a strategy for stabilizing proteins. The third protein society meeting, 19-22, September, Garmish-Partenkirchen, Germany.

Iwai, H., Sobol, A., Wider, G. and Wüthrich, K. (1998) The complete surface hydration shell of a protein by NMR spectroscopy. XVIII International Conference on Magnetic Resonance in Biological Systems. August 23-28, 1998, Tokyo Metropolitan University, Hachioji , Tokyo, Japan.

Last modified on