title: Autolytic degradation of ocriplasmin: a complex mechanism unraveled by mutational analysis.
abstract: Ocriplasmin, a truncated form of plasmin, is commercialized in the USA and in Europe under the trade name Jetrea(®), and indicated for the treatment of symptomatic vitreomacular adhesion and vitreomacular traction including when associated with macular hole ≤400 µm, respectively. We have shown in a previous study that ocriplasmin undergoes autolytic degradation when injected in eye vitreous, which leads to its rapid inactivation. In order to investigate this process further, we have introduced in ocriplasmin a variety of amino acid substitutions within or in the immediate vicinity of the three major autolytic cleavage sites. We demonstrate here that autolytic inactivation of ocriplasmin is a sequential process where initial cleavage occurs primarily between residues 156 and 157. Reduction or even blocking of autolysis can be achieved by mutating a limited number of key residues. In this study, we also report the identification of a series of ocriplasmin variants with improved resistance to autolysis and unimpaired catalytic activity. Such variants represent useful tools for the exploration of therapeutic approaches aiming at non-surgical resolution of vitreomacular adhesion.
authors.affiliation: Thrombogenics N.V., Gaston Geenslaan 1, 3001 Leuven, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Noppen
authors.affiliation: Thrombogenics N.V., Gaston Geenslaan 1, 3001 Leuven, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Fonteyn
authors.affiliation: Thrombogenics N.V., Gaston Geenslaan 1, 3001 Leuven, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Aerts
authors.affiliation: Thrombogenics N.V., Gaston Geenslaan 1, 3001 Leuven, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: De Vriese
authors.affiliation: Laboratory for Biomolecular Modeling, Katholieke Universiteit Leuven, Celestijnenlaan 200G, B-3001 Leuven, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: De Maeyer
authors.affiliation: Thrombogenics N.V., Gaston Geenslaan 1, 3001 Leuven, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Le Floch
authors.affiliation: Thrombogenics N.V., Gaston Geenslaan 1, 3001 Leuven, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Barbeaux
authors.affiliation: Thrombogenics N.V., Gaston Geenslaan 1, 3001 Leuven, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Zwaal
authors.affiliation: Thrombogenics N.V., Gaston Geenslaan 1, 3001 Leuven, Belgium marc.vanhove@thrombogenics.com.
authors.forename: M
authors.initials: M
authors.lastname: Vanhove
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain; D004252:DNA Mutational Analysis; D004789:Enzyme Activation; D005341:Fibrinolysin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017354:Point Mutation; D015202:Protein Engineering; D059748:Proteolysis; D014822:Vitreous Body / Q000201:enzymology
chemical_list: D010446:Peptide Fragments; C054561:microplasmin; D005341:Fibrinolysin
keywords: Jetrea®; autolysis; ocriplasmin variants; posterior vitreous detachment; symptomatic vitreomacular adhesion