Variant LovD polypeptides and their uses
The present disclosure provides acyltransferases useful for synthesizing therapeutically important statin compound.
1. An engineered variant LovD polypeptide having at least two-fold greater catalytic activity than the wild-type Aspergillus terreus acyltransferase of the amino acid sequence of SEQ ID NO: 2, wherein said engineered variant LovD polypeptide has at least 90% sequence identity to the wild-type Aspergillus terreus acyltransferase of the amino acid sequence of SEQ ID NO: 2, and wherein said engineered variant LovD polypeptide comprises the substitution A247S.
2. The engineered variant LovD polypeptide of claim 1 , wherein said engineered variant LovD polypeptide has at least 10-fold greater catalytic activity than the wild-type A. terreus acyltransferase of the amino acid sequence of SEQ ID NO:2.
3. The engineered variant LovD polypeptide of claim 1 , wherein said engineered variant LovD polypeptide further comprises:
(i) one or more substitutions that correlate with an increase in catalytic activity as compared to the wild-type Aspergillus terreus acyltransferase of the amino acid sequence of SEQ ID NO: 2;
(ii) one or more substitutions that correlate with increased thermal stability as compared to the wild-type Aspergillus terreus acyltransferase of the amino acid sequence of SEQ ID NO: 2;
(iii) one or more substitutions that correlate with reduced aggregation as compared to the wild-type Aspergillus terreus acyltransferase of the amino acid sequence of SEQ ID NO:2;
(iv) one or more substitutions that correlate with increased enzyme stability as compared to the wild-type Aspergillus terreus acyltransferase of the amino acid sequence of SEQ ID NO: 2; and
(v) one or more substitutions selected from the group consisting of 14N, A9V, K26E, R28K, R28S, 135L, C40A, C40V, C40F, S41R, N43Y, C60F, C60Y, C60N, C60H, S109C, A123P, S142N, A184T, A184V, N191S, A261T, A261E, A261V, L292R, Q297E, L335M, A377V, A383V, N391D and H404R.
4. The engineered variant LovD polypeptide of claim 1 , which further comprises:
(i) at least one substitutions selected from the group consisting of M157V, S164G, S172N, L174F, A178L, N191G, L192I, R250K, S256T, A261H, G275S, Q297G, L361M, V370I and N391S;
(ii) at least one substitutions selected from the group consisting of Q241M, A261H, Q295R and Q412R;
(iii) at least one substitutions selected from the group consisting of N43R, D96R and H404K;
(iv) at least one substitutions selected from the group consisting of C40R, C60R and D245E; and
(v) at least one substitutions selected from the group consisting of 14N, A9V, K26E, R28K, R28S, I35L, C40A, C40V, C40F, S41R, N43Y, C60F, C60Y, C60N, C60H, S109C, A123P, S142N, A184T, A184V, N191S, A261T, A261E, A261V, L292R, Q297E, L335M, A377V, A383V, N391D and H404R.
5. The engineered variant LovD polypeptide of claim 1 comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, and 120.
6. A method of making simvastatin comprising contacting a monacolin J substrate with the engineered variant LovD polypeptide of claim 1 in the presence of an α-dimethylbutyryl thioester co-substrate and under conditions in which the monacolin J is converted to simvastatin.
7. The method of claim 6 , wherein said monacolin J is a sodium salt.
8. The method of claim 7 , wherein said monacolin J is a sodium salt and activated charcoal is added.
9. The method of claim 8 , wherein said monacolin J is an ammonium salt.
10. The method of claim 6 , wherein an agent for precipitating simvastatin is added.
11. The method of claim 10 , wherein said agent is ammonium hydroxide.