title: In vitro studies of antifreeze glycoprotein (AFGP) and a C-linked AFGP analogue.
abstract: Antifreeze glycoproteins (AFGPs) are a subclass of biological antifreezes found in deep sea Teleost fish. These compounds have the ability to depress the freezing point of the organism such that it can survive the subzero temperatures encountered in its environment. This physical property is very attractive for the cryopreservation of cells, tissues, and organs. Recently, our laboratory has designed and synthesized a functional carbon-linked (C-linked) AFGP analogue (1) that demonstrates tremendous promise as a novel cryoprotectant. Herein we describe the in vitro effects and interactions of C-linked AFGP analogue 1 and native AFGP 8. Our studies reveal that AFGP 8 is cytotoxic to human embryonic liver and human embryonic kidney cells at concentrations higher than 2 and 0.63 mg/mL, respectively, whereas lower concentrations are not toxic. The mechanism of this cytotoxicity is consistent with apoptosis because caspase-3/7 levels are significantly elevated in cell cultures treated with AFGP 8. In contrast, C-linked AFGP analogue 1 displayed no in vitro cytotoxicity even at high concentrations, and notably, caspase-3/7 activities were suppressed well below background levels in cell lines treated with 1. Although the results from these studies limit the human applications of native AFGP, they illustrate the benefits of developing functional C-linked AFGP analogues for various medical, commercial and industrial applications.
authors.affiliation: Department of Chemistry, University of Ottawa, Ottawa, ON KIN 6N5, Canada.
authors.forename: Suhuai
authors.initials: S
authors.lastname: Liu
authors.forename: Wenjun
authors.initials: W
authors.lastname: Wang
authors.forename: Elisabeth von
authors.initials: Ev
authors.lastname: Moos
authors.forename: Jessica
authors.initials: J
authors.lastname: Jackman
authors.forename: Geoff
authors.initials: G
authors.lastname: Mealing
authors.forename: Robert
authors.initials: R
authors.lastname: Monette
authors.forename: Robert N
authors.initials: RN
authors.lastname: Ben
mesh_terms: D000818:Animals; D021301:Antifreeze Proteins / Q000032:analysis / Q000138:chemical synthesis / Q000378:metabolism* / Q000633:toxicity*; D017209:Apoptosis; D053148:Caspase 3 / Q000032:analysis / Q000378:metabolism; D053179:Caspase 7 / Q000032:analysis / Q000378:metabolism; D002478:Cells, Cultured; D003451:Cryoprotective Agents / Q000138:chemical synthesis / Q000378:metabolism* / Q000633:toxicity*; D006023:Glycoproteins / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D006801:Humans
chemical_list: D021301:Antifreeze Proteins; C521878:C-linked AFGP analog 1; D003451:Cryoprotective Agents; D006023:Glycoproteins; D053148:Caspase 3; D053179:Caspase 7