10395-43-4Relevant articles and documents
Identification of Chimeric αβγ Diterpene Synthases Possessing both Type II Terpene Cyclase and Prenyltransferase Activities
Mitsuhashi, Takaaki,Okada, Masahiro,Abe, Ikuro
, p. 2104 - 2109 (2017/10/07)
Two unusual diterpene synthases composed of three domains (α, β, and γ) were identified from fungal Penicillium species. They are the first enzymes found to possess both type II terpene cyclase (TC) and prenyltransferase (PT) activities. These enzymes were characterized by heterologous expression in Aspergillus oryzae and in vitro experiments with wild-type, mutated, and truncated enzymes. The results revealed that the α domain in the C-terminal region of these enzymes was responsible for the PT activity, whereas the βγ domains in the N-terminal region composed the type II TC, and formed copalyl diphosphate (2). Additionally, between the α and βγ domains, there is a characteristic linker region, in which minimal secondary structure is predicted. This linker does not exist in the characterized three-domain (αβγ) terpene synthases known as monofunctional type I or type II TCs, or bifunctional type I and type II TC enzymes. Therefore, both the catalytic activities and protein architecture substantially differentiate these new enzymes from the previously characterized terpene synthases.
Substrate specificity of Rv3378c, an enzyme from Mycobacterium tuberculosis, and the inhibitory activity of the bicyclic diterpenoids against macrophage phagocytosis
Hoshino, Tsutomu,Nakano, Chiaki,Ootsuka, Takahiro,Shinohara, Yosuke,Hara, Takashi
experimental part, p. 2156 - 2165 (2011/05/14)
The Rv3378c gene product from Mycobacterium tuberculosis encodes a diterpene synthase to produce tuberculosinol (3), 13R-isotuberculosinol (4a), and 13S-isotuberculosinol (4b) from tuberculosinyl diphosphate (2). The product distribution ratios are 1:1 for 3 to 4 and 1:3 for 4a to 4b. The substrate specificity of the Rv3378c-encoded enzyme was examined. The 3 labdadienyl diphosphates, copalyl diphosphate (CDP) (7), ent-CDP (8), and syn-CDP (9), underwent the conversion reaction, with good yields (67-78%). Copalol (23) and manool (24) were produced from 7, ent-copalol (25) and ent-manool (26) from 8, and syn-copalol (27) and vitexifolin A (28) from 9. The ratio of 23 to 24 was 40:27, that of 25:26 was 22:50, and that of 27:28 was 16:62. Analysis on a GC-MS chromatograph equipped with a chiral column revealed that 24, 26, and 28 consisted of a mixture of 13R- (a) and 13S-stereoisomers (b) in the following ratio: ca. 1:1 for 24a to 24b, ca. 1:5 for 26a to 26b, and ca. 1:19 for 28a to 28b. The structures of these products indicate that the reactions of the 3 CDPs proceeded in the same fashion as that of 2. This is the first report on the enzymatic synthesis of natural diterpenes manool, ent-manool, and vitexifolin A. Both Rv3377c and Rv3378c genes are found in virulent Mycobacterium species, but not in avirulent species. We found that 3 and 4 inhibited the phagocytosis of opsonized zymosan particles by human macrophage-like cells. Interestingly, the inhibitory activity was synergistically increased by the coexistence of 3 and 4b. Other labdane-related diterpenes, 13-16 and 23-28, had little or no inhibitory activity. This synergistic inhibition by 3 and 4 may provide further advantage to the impairment of phagocyte function, which might contribute to pathogenicity of M. tuberculosis.
