Modified sulfamidase and production thereof

Abstract

Disclosed herein are a modified sulfamidase, a composition comprising a modified sulfamidase, as well as methods for preparing a modified sulfamidase and therapeutic use of such a sulfamidase. In particular, the present disclosure relates to a modified sulfamidase comprising substantially no epitopes for glycan recognition receptors, thereby enabling transportation of said sulfamidase across the blood brain barrier of a mammal, wherein said sulfamidase has catalytic activity in the brain of said mammal.

1 . A modified sulfamidase comprising a relative content of natural glycan moieties of around 25% or less of the content of natural glycan moieties in unmodified recombinant sulfamidase, and wherein the modified sulfamidase comprises one or more oligomannose glycans that are disrupted by single bond breaks and double bond breaks, the extent of single bond breaks per total bond breaks being at least 60%. 
     
     
         2 . The modified sulfamidase according to  claim 1 , comprising substantially no epitopes for glycan recognition receptors. 
     
     
         3 . The modified sulfamidase according to  claim 2 , wherein said epitopes are selected from the group consisting of a mannose-6-phosphate moiety, a mannose moiety and a galactose moiety. 
     
     
         4 . The modified sulfamidase according to  claim 3 , comprising no mannose-6-phosphate moieties, mannose moieties or galactose moieties. 
     
     
         5 . The modified sulfamidase according to  claim 3 , wherein said epitopes are recognized by at least one glycan recognition receptor selected from the group consisting of mannose-6 phosphate receptor type 1, mannose-6 phosphate receptor type 2, mannose receptor and galactose receptor. 
     
     
         6 . The modified sulfamidase according to  claim 1 , comprising a polypeptide consisting of an amino acid sequence as defined in SEQ ID NO: 1, or a polypeptide having at least 95% sequence identity with an amino acid sequence as defined in SEQ ID NO: 1. 
     
     
         7 . The modified sulfamidase according to  claim 6 , wherein said epitopes are absent at at least four of the five N-glycosylation sites: N in position 21 (N(21)), N in position 122 (N(122)), N in position 131 (N(131)), N in position 244 (N(244)), and N in position 393 (N(393)) of SEQ ID NO:1. 
     
     
         8 . The modified sulfamidase according to  claim 7 , wherein said epitopes are absent at N-glycosylation sites N(21), N(122), N(244), and N(393) of said modified sulfamidase polypeptide. 
     
     
         9 . The modified sulfamidase according to  claim 6 , comprising an oligomannose glycan at the N(131) site that is disrupted by single bond breaks and double bond breaks, the disruption being characterized by an extent of single bond breaks per total bond breaks of at least 60%. 
     
     
         10 . The modified sulfamidase according to  claim 6 , said sulfamidase being intact in its c-terminal part, said C-terminal part optionally being represented by amino acids 436-484 of SEQ ID NO: 1. 
     
     
         11 . The modified sulfamidase according to  claim 6 , comprising a Ca-formylglycine residue in position 50 of SEQ ID NO: 1 (FGly50). 
     
     
         12 . A sulfamidase composition, comprising modified sulfamidase having substantially no epitopes for glycan recognition receptors, and having a Ca-formylglycine (FGly) to serine (Ser) ratio at the active site that is greater than 1. 
     
     
         13 . The sulfamidase composition according to  claim 12 , comprising no more than 5% by weight of sulfamidase in multimeric forms having a molecular weight of above 10 10  kDa. 
     
     
         14 .- 27 . (canceled) 
     
     
         28 . A method of treating a lysosomal storage disease, comprising administering to a mammal in need thereof a therapeutically effective amount of:
 a) a modified sulfamidase comprising a relative content of natural glycan moieties of around 25% or less of the content of natural glycan moieties in unmodified recombinant sulfamidase, and wherein the modified sufamidase comprises one or more oligomannose glycans that are disrupted by single bond breaks and double bond breaks, the extent of single bond breaks being at least 60%, or   b) a sulfamidase composition, comprising modified sulfamidase having substantially no epitopes for glycan recognition receptors, and having a Ca-formylglycine (FGly) to serine (Ser) ratio at the active site that is greater than 1.   
     
     
         29 . The method of  claim 28 , wherein the lysosomal storage disease is mucopolysaccharidosis IIIA.