Disaccharide Residues are Required for Native Antifreeze Glycoprotein Activity

Antifreeze glycoproteins (AFGPs) are glycosylated polypeptides produced by Antarctic and Arctic fishes, which allow them to survive in seawater at sub-zero temperatures. An investigation into the postulated enteric uptake of AFGP synthesized in the exocrine pancreas of Antarctic fishes required a custom-prepared AFGP probe that incorporated seven isotopically-labelled Ala residues for detection by mass spectrometry. The AFGPs are composed of a repetitive three amino acid unit (Ala-Ala-Thr), in which the threonine residue is glycosylated with the disaccharide β-d-Gal-(1→3)-α-d-GalNAc. The synthesis of isotopically-labelled AFGP8 (1), as well as the optimized synthesis of the protected glycosylated amino acid building block 2, is reported.

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Antifreeze glycoprotein biosynthesis in antarctic fishes

Comparative Biochemistry and Physiology Part B Comparative Biochemistry ◽

10.1016/0305-0491(79)90308-0 ◽

1979 ◽

Vol 62 (2) ◽

pp. 179-183 ◽

Cited By ~ 7

Author(s):

Alan P. Hudson ◽

Arthur L. DeVries ◽

Audrey E.V. Haschemeyer

Keyword(s):

Antarctic Fishes ◽

Antifreeze Glycoprotein ◽

Glycoprotein Biosynthesis

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Crystal-plane-dependent effects of antifreeze glycoprotein impurity for ice growth dynamics

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2018.0393 ◽

2019 ◽

Vol 377 (2146) ◽

pp. 20180393 ◽

Cited By ~ 1

Author(s):

Yoshinori Furukawa ◽

Ken Nagashima ◽

Shunichi Nakatsubo ◽

Salvador Zepeda ◽

Ken-ichiro Murata ◽

...

Keyword(s):

Crystal Growth ◽

Growth Rates ◽

Space Station ◽

Supercooled Water ◽

Normal Growth ◽

Crystal Plane ◽

Impurity Effect ◽

Crystal Formation ◽

Ice Crystal ◽

Antifreeze Glycoprotein

An impurity effect on ice crystal growth in supercooled water is an important subject in relation to ice crystal formation in various conditions in the Earth's cryosphere regions. In this review, we consider antifreeze glycoprotein molecules as an impurity. These molecules are well known as functional molecules for controlling ice crystal growth by their adsorption on growing ice/water interfaces. Experiments on free growth of ice crystals in supercooled water containing an antifreeze protein were conducted on the ground and in the International Space Station, and the normal growth rates for the main crystallographic faces of ice, namely, basal and prismatic faces, were precisely measured as functions of growth conditions and time. The crystal-plane-dependent functions of AFGP molecules for ice crystal growth were clearly shown. Based on the magnitude relationship for normal growth rates among basal, prismatic and pyramidal faces, we explain the formation of a dodecahedral external shape of an ice crystal in relation to the key principle governing the growth of polyhedral crystals. Finally, we emphasize that the crystal-plane dependence of the function of antifreeze proteins on ice crystal growth relates to the freezing prevention of living organisms in sub-zero temperature conditions. This article is part of the theme issue ‘The physics and chemistry of ice: scaffolding across scales, from the viability of life to the formation of planets’.

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Resistance of Tick Gut Microbiome to Anti-Tick Vaccines, Pathogen Infection and Antimicrobial Peptides

Pathogens ◽

10.3390/pathogens9040309 ◽

2020 ◽

Vol 9 (4) ◽

pp. 309 ◽

Cited By ~ 4

Author(s):

Agustín Estrada-Peña ◽

Alejandro Cabezas-Cruz ◽

Dasiel Obregón

Keyword(s):

Antimicrobial Peptides ◽

Biofilm Formation ◽

Ixodes Scapularis ◽

Taxonomic Composition ◽

Bacterial Biofilm ◽

Pathogen Infection ◽

Polysaccharide Biosynthesis ◽

Antifreeze Glycoprotein ◽

Highly Sensitive ◽

Tick Microbiome

Ixodes scapularis ticks harbor microbial communities including pathogenic and non-pathogenic microbes. Pathogen infection increases the expression of several tick gut proteins, which disturb the tick gut microbiota and impact bacterial biofilm formation. Anaplasma phagocytophilum induces ticks to express I. scapularis antifreeze glycoprotein (IAFGP), a protein with antimicrobial activity, while Borrelia burgdorferi induces the expression of PIXR. Here, we tested the resistance of I. scapularis microbiome to A. phagocytophilum infection, antimicrobial peptide IAFGP, and anti-tick immunity specific to PIXR. We demonstrate that A. phagocytophilum infection and IAFGP affect the taxonomic composition and taxa co-occurrence networks, but had limited impact on the functional traits of tick microbiome. In contrast, anti-tick immunity disturbed the taxonomic composition and the functional profile of tick microbiome, by increasing both the taxonomic and pathways diversity. Mechanistically, we show that anti-tick immunity increases the representation and importance of the polysaccharide biosynthesis pathways involved in biofilm formation, while these pathways are under-represented in the microbiome of ticks infected by A. phagocytophilum or exposed to IAFGP. These analyses revealed that tick microbiota is highly sensitive to anti-tick immunity, while it is less sensitive to pathogen infection and antimicrobial peptides. Results suggest that biofilm formation may be a defensive response of tick microbiome to anti-tick immunity.

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In SituGene Mapping of Two Genes Supports Independent Evolution of Sex Chromosomes in Cold-Adapted Antarctic Fish

BioMed Research International ◽

10.1155/2013/243938 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Laura Ghigliotti ◽

C.-H. Christina Cheng ◽

Céline Bonillo ◽

Jean-Pierre Coutanceau ◽

Eva Pisano

Keyword(s):

Sex Chromosome ◽

Antarctic Fish ◽

5S Rdna ◽

Cold Adapted ◽

Antifreeze Glycoprotein ◽

Y Chromosomes ◽

Pagothenia Borchgrevinki ◽

History Of ◽

Sex Chromosome System

Two genes, that is, 5S ribosomal sequences and antifreeze glycoprotein (AFGP) genes, were mapped onto chromosomes of eight Antarctic notothenioid fish possessing a X1X1X2X2/X1X2Y sex chromosome system, namely,Chionodraco hamatusandPagetopsis macropterus(family Channichthyidae),Trematomus hansoni,T. newnesi,T. nicolai,T. lepidorhinus, andPagothenia borchgrevinki(family Nototheniidae), andArtedidraco skottsbergi(family Artedidraconidae). Through fluorescencein situhybridization (FISH), we uncovered distinct differences in the gene content of the Y chromosomes in the eight species, withC. hamatusandP. macropterusstanding out among others in bearing 5S rDNA and AFGP sequences on their Y chromosomes, respectively. Both genes were absent from the Y chromosomes of any analyzed species. The distinct patterns of Y and non-Y chromosome association of the 5S rDNA and AFGP genes in species representing different Antarctic fish families support an independent origin of the sex heterochromosomes in notothenioids with interesting implications for the evolutionary/adaptational history of these fishes living in a cold-stable environment.

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