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US 10,301,607 B2Granted
Methods of generating and screening for lytic chimeric polypeptides
AssigneeHypharm GmbH
InventorsAnna Scherzinger, Sonja Molinaro, Bernd Buchberger
Life of this patent
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Abstract
The present invention relates to novel methods of generating and screening for chimeric polypeptides, which can be used in the treatment and prophylaxis of pathogenic bacterial contamination, colonization and infection. The novel methods are based on random recombination of protein domains, and the chimeric polypeptides obtainable by the methods according to the invention are characterized in that they comprise at least one enzymatic active domain (EAD) and at least one cell binding domain (CBD). The present invention also relates to a library of chimeric polypeptides obtainable by the methods of the present invention.
Claims13
A lytic chimeric polypeptide obtained by a method of screening for a lytic chimeric polypeptide comprising the steps of:
- (a) providing one or more DNA sequences each encoding at least one cell binding domain (CBD) and one or more DNA sequences each encoding at least one enzymatic active domain (EAD), wherein the EAD is selected from the group consisting of
- (i) the lytic domain of a bacteriophage lysin, and
- (ii) a bacteriophage tail-associated protein having lytic activity;
- (b) amplifying a first (1st) domain sequence selected from the domain sequences of (a) using a pair of primers designed to introduce different restriction sites at the 5′-end and at the 3′-end, and a tag labeling at the 5′-end or at the 3′-end;
- (c) amplifying a second (2nd) domain sequence selected from the domain sequences of (a) using a pair of primers designed to introduce:
- (i) in case of 5′-end labelling of the 1st domain:
- at the 5′-end the same restriction site as at the 3′-end of the 1st domain, and at the 3′-end a restriction site different from the restriction sites introduced into the 1st domain sequence,
- (ii) in case of 3′-end labelling of the 1st domain:
- at the 3′-end the same restriction site as at the 5′-end of the 1st domain, and at the 5′-end a restriction site different from the restriction sites introduced into the 1st domain sequence;
- (d) amplifying a third (3rd) domain sequence selected from the domain sequences of (a) using a pair of primers designed to introduce:
- in case of 5′-end labelling of the 1st domain:
- at the 5′-end the same restriction site as at the 3′-end of the preceding 2nd domain, and at the 3′-end a restriction site that is different from that at the 5′-end of the 1st domain,
- (ii) in case of 3′-end labelling of the 1st domain:
- at the 3′-end the same restriction site as at the 5′-end of the preceding 2nd domain, and at the 5′-end a restriction site that is different from that at the 3′-end of the 1st domain;
- wherein the pair of primers is further designed such that the restriction sites are different at the 5′-end and the 3′-end of the 3rd domain sequence;
- (e) optionally amplifying one or more further domain sequences selected from the domain sequences of (a) for extending the series of domain sequences according to steps (b) to (d), using for each of said one or more further domain sequences a pair of primers designed following the principle of steps (c) and (d) so as to introduce:
- (i) in case of 5′-end labelling of the 1st domain:
- at the 5′-end the same restriction site as at the 3′-end of the preceding domain, and at the 3′-end a restriction site that is different from that at the 5′-end of the 1st domain,
- (ii) in case of 3′-end labelling of the 1st domain:
- at the 3′-end the same restriction site as at the 5′-end of the preceding domain, and at the 5′-end a restriction site that is different from that at the 3′-end of the 1st domain;
- wherein the pair of primers is further designed such that the restriction sites are different at the 5′-end and the 3′-end of each of said one or more further domain sequences;
- (f) performing a restriction digest of the amplified domain sequences of any of steps (b) to (e) with restriction enzymes targeting the restriction sites introduced in any of steps (b) to (e), wherein a restriction digest is not performed on the restriction site introduced to an end carrying a tag labelling;
- (g) ligating the digested 1st and 2nd domain sequence obtained in step (f) to obtain a ligation product comprising the 1st and 2nd domain sequence;
- (h) binding the ligation product of step (g) to a solid support using the tag labeling of the 1st domain sequence to obtain a bound ligation product comprising the 1st and 2nd domain sequence;
- (j) ligating the digested 3rd domain sequence of (d) obtained in step (f) to the bound ligation product of step (h) to obtain a bound ligation product comprising the 1st, 2nd and 3rd domain sequence;
- (k) optionally ligating one or more digested domain sequences of (e) obtained in step (f) to the bound ligation product of step (j) to obtain a bound ligation product comprising one or more further domain sequences of (e);
- (l) releasing the ligation product obtained in any of steps (h) to (k) from the solid support;
- (m) cloning the ligation product obtained in step (l) into an expression vector;
- (n) introducing the vector obtained in step (m) into an expression host, preferably into a bacterial expression host;
- (o) culturing the expression host of step (n) carrying the vector obtained in step (m) under conditions suitable to allow expression of a lytic polypeptide encoded by the domain sequences of the cloned ligation product;
- (p) selecting and isolating an expression clone expressing a lytic polypeptide according to step (o) using the lytic activity of the polypeptide;
- and
- (q) characterizing the lytic polypeptide expressed by the isolated expression clone of step (p) and identifying a lytic chimeric polypeptide.
30 more elements
A chimeric polypeptide or a plurality of chimeric polypeptides obtained by the method of generating chimeric polypeptides having at least one CBD and at least one EAD comprising the steps of
- (a) providing one or more DNA sequences each encoding at least one CBD and one or more DNA sequences each encoding at least one EAD, and optionally one or more DNA sequences each encoding at least one CBD and at least one EAD, wherein the EAD is selected from the group consisting of
- (i) the lytic domain of a bacteriophage lysin;
- and
- (ii) a bacteriophage tail-associated protein having lytic activity:
- (b) amplifying a first (1st) domain sequence selected from the domain sequences of (a) using a pair of primers designed to introduce different restriction sites at the 5′-end and at the 3′-end, and a tag labeling at the 5′-end or at the 3′-end;
- (c) amplifying a second (2nd) domain sequence selected from the domain sequences of (a) using a pair of primers designed to introduce:
- (i) in case of 5′-end labelling of the 1st domain:
- at the 5′-end the same restriction site as at the 3′-end of the first domain, and at the 3′-end a restriction site different from the restriction sites introduced into the domain sequence,
- (ii) in case of 3′-end labelling of the 1st domain:
- at the 3′-end the same restriction site as at the 5′-end of the 1st domain, and at the 5′-end a restriction site different from the restriction sites introduced into the domain sequence;
- (d) optionally amplifying a third (3rd) domain sequence selected from the domain sequences of (a) using a pair of primers designed to introduce:
- (i) in case of 5′-end labelling of the 1st domain:
- at the 5′-end the same restriction site as at the 3′-end of the preceding 2nd domain, and at the 3′-end a restriction site that is different from that at the 5′-end of the 1st domain,
- (ii) in case of 3′-end labelling of the 1st domain:
- at the 3′-end the same restriction site as at the 5′-end of the preceding 2nd domain, and at the 5′-end a restriction site that is different from that at the 3′-end of the 1st domain;
- wherein the pair of primers is further designed such that the restriction sites are different at the 5′-end and the 3′-end of the 3rd domain sequence;
- (e) optionally amplifying one or more further domain sequences selected from the domain sequences of (a) for extending the series of domain sequences according to steps (b) to (d), using for each of said one or more further domain sequences a pair of primers designed following the principle of steps (c) and (d) so as to introduce:
- (i) in case of 5′-end labelling of the 1st domain:
- at the 5′-end the same restriction site as at the 3′-end of the preceding domain, and at the 3′-end a restriction site that is different from that at the 5′-end of the 1st domain,
- (ii) in case of 3′-end labelling of the 1st domain:
- at the 3′-end the same restriction site as at the 5′-end of the preceding domain, and at the 5′-end a restriction site that is different from that at the 3′-end of the 1st domain;
- wherein the pair of primers is further designed such that the restriction sites are different at the 5′-end and the 3′-end of each of said one or more further domain sequences;
- (f) performing a restriction digest of the amplified domain sequences of any of steps (b) to (e) using restriction enzymes targeting the restriction sites introduced in any of steps (b) to (e), wherein a restriction digest is not performed on the restriction site introduced to an end carrying a tag labelling;
- (g) ligating the digested 1st and 2nd domain sequence obtained in step (f) to obtain a ligation product comprising the 1st and 2nd domain sequence;
- (h) binding the ligation products of step (g) to a solid support using the tag labeling of the 1st domain sequence to obtain a bound ligation product comprising the 1st and 2nd domain sequence;
- (j) optionally ligating the digested 3rd domain sequence of (d) obtained in step (f) to the bound ligation product of step (h) to obtain a bound ligation product comprising the 1st, 2nd and 3rd domain sequence;
- (k) optionally ligating one or more digested domain sequences of (e) obtained in step (f) to the bound ligation product of step (j) to obtain a bound ligation product comprising one or more further domain sequences of (e);
- (l) releasing the ligation product obtained in any one of steps (h) to (k) from the solid support;
- and
- (m) characterizing the ligation product obtained in step (l) and identifying chimeric polypeptides having at least one CBD and at least one EAD.
27 more elements
Dependencies are inferred from the claim text.