Effects of Ice Nucleation Protein Repeat Number and Oligomerization Level on Ice Nucleation Activity

M. L. Ling; H. Wex; S. Grawe; J. Jakobsson; J. Londahl; S. Hartmann; K. Finster; T. Boesen; T. Santl-Temkiv

doi:10.1002/2017JD027307

Effects of Ice Nucleation Protein Repeat Number and Oligomerization Level on Ice Nucleation Activity

M. L. Ling, H. Wex, S. Grawe, J. Jakobsson, J. Londahl, S. Hartmann, K. Finster, T. Boesen^*, T. Santl-Temkiv

^*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review

Abstract

Ice nucleation active bacteria have attracted particular attention due to their unique ability to produce specific ice nucleation proteins (INpros), which are the most efficient ice nuclei known as they induce nucleation at temperatures close to 0°C. Our model bacterium Pseudomonas syringae strain R10.79 produced INpros containing 67 tandem repeats, forming the proposed ice-binding surface. To understand the role of the INpro repeats as well as the role of intermolecular interactions between INpros for their ice nucleation behavior, we produced a truncated version of the protein with only 16 tandem repeats (INpro _16R). The purified INpro _16R produced oligomers of varying sizes. Immersion freezing ice nucleation behavior of purified INpro _16R was characterized by droplet-freezing assays and in the Leipzig Aerosol Cloud Interaction Simulator. Predominant INpro _16R oligomers introduced into Leipzig Aerosol Cloud Interaction Simulator as single particles with diameters of 50 nm or 70 nm were ice nucleation active at temperatures of −26°C and −24°C, respectively. These are much lower temperatures compared to that of intact INpros (−12°C). The data clearly indicated that the number of repeats determines the ice nucleation temperature. In addition, ice nucleation between −9°C and −10°C, comparable to the activity of intact INpro, was caused by higher-order INpro _16R oligomers. This supported previous observations that INpro oligomerization increases the ice-binding surface, thereby affecting ice nucleation activity. In conclusion, both repeat number and oligomerization contribute in a seemingly independent manner to the nucleation mechanism of INpros.

Originalsprog	Engelsk
Tidsskrift	Journal of Geophysical Research: Atmospheres
Vol/bind	123
Nummer	3
Sider (fra-til)	1802-1810
Antal sider	9
ISSN	2169-897X
DOI	https://doi.org/10.1002/2017JD027307
Status	Udgivet - 16 feb. 2018

Adgang til dokumentet

10.1002/2017JD027307

Aeromikrobiologi
Santl-Temkiv, T. (Projektleder), Finster, K. (Projektleder), Bilde, M. (PI), Weidner, T. (PI), Boesen, T. (PI), Melvad, C. (PI), Nielsen, M. B. (PI), Im, U. (PI), Sahyoun, M. (PI), Tesson, S. V. (PI), Dreyer, L. S. A. (PI), Rosati, B. (PI), Dwivedi, A. K. (PI), Jensen, L. Z. (PI) & Wieber, C. (PI)
Projekter: Projekt › Forskning

Citationsformater

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title = "Effects of Ice Nucleation Protein Repeat Number and Oligomerization Level on Ice Nucleation Activity",

abstract = "Ice nucleation active bacteria have attracted particular attention due to their unique ability to produce specific ice nucleation proteins (INpros), which are the most efficient ice nuclei known as they induce nucleation at temperatures close to 0°C. Our model bacterium Pseudomonas syringae strain R10.79 produced INpros containing 67 tandem repeats, forming the proposed ice-binding surface. To understand the role of the INpro repeats as well as the role of intermolecular interactions between INpros for their ice nucleation behavior, we produced a truncated version of the protein with only 16 tandem repeats (INpro 16R). The purified INpro 16R produced oligomers of varying sizes. Immersion freezing ice nucleation behavior of purified INpro 16R was characterized by droplet-freezing assays and in the Leipzig Aerosol Cloud Interaction Simulator. Predominant INpro 16R oligomers introduced into Leipzig Aerosol Cloud Interaction Simulator as single particles with diameters of 50 nm or 70 nm were ice nucleation active at temperatures of −26°C and −24°C, respectively. These are much lower temperatures compared to that of intact INpros (−12°C). The data clearly indicated that the number of repeats determines the ice nucleation temperature. In addition, ice nucleation between −9°C and −10°C, comparable to the activity of intact INpro, was caused by higher-order INpro 16R oligomers. This supported previous observations that INpro oligomerization increases the ice-binding surface, thereby affecting ice nucleation activity. In conclusion, both repeat number and oligomerization contribute in a seemingly independent manner to the nucleation mechanism of INpros.",

keywords = "precipitation, bioaerosols, PSEUDOMONAS-SYRINGAE, BACTERIA, PRECIPITATION, NUCLEI, PLANTS, IMPACT, MODEL",

author = "Ling, {M. L.} and H. Wex and S. Grawe and J. Jakobsson and J. Londahl and S. Hartmann and K. Finster and T. Boesen and T. Santl-Temkiv",

year = "2018",

month = feb,

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doi = "10.1002/2017JD027307",

language = "English",

volume = "123",

pages = "1802--1810",

journal = "Journal of Geophysical Research: Atmospheres",

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TY - JOUR

T1 - Effects of Ice Nucleation Protein Repeat Number and Oligomerization Level on Ice Nucleation Activity

AU - Ling, M. L.

AU - Wex, H.

AU - Grawe, S.

AU - Jakobsson, J.

AU - Londahl, J.

AU - Hartmann, S.

AU - Finster, K.

AU - Boesen, T.

AU - Santl-Temkiv, T.

PY - 2018/2/16

Y1 - 2018/2/16

N2 - Ice nucleation active bacteria have attracted particular attention due to their unique ability to produce specific ice nucleation proteins (INpros), which are the most efficient ice nuclei known as they induce nucleation at temperatures close to 0°C. Our model bacterium Pseudomonas syringae strain R10.79 produced INpros containing 67 tandem repeats, forming the proposed ice-binding surface. To understand the role of the INpro repeats as well as the role of intermolecular interactions between INpros for their ice nucleation behavior, we produced a truncated version of the protein with only 16 tandem repeats (INpro 16R). The purified INpro 16R produced oligomers of varying sizes. Immersion freezing ice nucleation behavior of purified INpro 16R was characterized by droplet-freezing assays and in the Leipzig Aerosol Cloud Interaction Simulator. Predominant INpro 16R oligomers introduced into Leipzig Aerosol Cloud Interaction Simulator as single particles with diameters of 50 nm or 70 nm were ice nucleation active at temperatures of −26°C and −24°C, respectively. These are much lower temperatures compared to that of intact INpros (−12°C). The data clearly indicated that the number of repeats determines the ice nucleation temperature. In addition, ice nucleation between −9°C and −10°C, comparable to the activity of intact INpro, was caused by higher-order INpro 16R oligomers. This supported previous observations that INpro oligomerization increases the ice-binding surface, thereby affecting ice nucleation activity. In conclusion, both repeat number and oligomerization contribute in a seemingly independent manner to the nucleation mechanism of INpros.

AB - Ice nucleation active bacteria have attracted particular attention due to their unique ability to produce specific ice nucleation proteins (INpros), which are the most efficient ice nuclei known as they induce nucleation at temperatures close to 0°C. Our model bacterium Pseudomonas syringae strain R10.79 produced INpros containing 67 tandem repeats, forming the proposed ice-binding surface. To understand the role of the INpro repeats as well as the role of intermolecular interactions between INpros for their ice nucleation behavior, we produced a truncated version of the protein with only 16 tandem repeats (INpro 16R). The purified INpro 16R produced oligomers of varying sizes. Immersion freezing ice nucleation behavior of purified INpro 16R was characterized by droplet-freezing assays and in the Leipzig Aerosol Cloud Interaction Simulator. Predominant INpro 16R oligomers introduced into Leipzig Aerosol Cloud Interaction Simulator as single particles with diameters of 50 nm or 70 nm were ice nucleation active at temperatures of −26°C and −24°C, respectively. These are much lower temperatures compared to that of intact INpros (−12°C). The data clearly indicated that the number of repeats determines the ice nucleation temperature. In addition, ice nucleation between −9°C and −10°C, comparable to the activity of intact INpro, was caused by higher-order INpro 16R oligomers. This supported previous observations that INpro oligomerization increases the ice-binding surface, thereby affecting ice nucleation activity. In conclusion, both repeat number and oligomerization contribute in a seemingly independent manner to the nucleation mechanism of INpros.

KW - precipitation

KW - bioaerosols

KW - PSEUDOMONAS-SYRINGAE

KW - BACTERIA

KW - PRECIPITATION

KW - NUCLEI

KW - PLANTS

KW - IMPACT

KW - MODEL

U2 - 10.1002/2017JD027307

DO - 10.1002/2017JD027307

M3 - Journal article

SN - 2169-897X

VL - 123

SP - 1802

EP - 1810

JO - Journal of Geophysical Research: Atmospheres

JF - Journal of Geophysical Research: Atmospheres

IS - 3

ER -

Effects of Ice Nucleation Protein Repeat Number and Oligomerization Level on Ice Nucleation Activity

Abstract

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Fingeraftryk

Projekter

Aeromikrobiologi

Citationsformater