RHC-80267 and N-bromosuccinimide inhibited LipN enzyme activity completely. Interestingly, Trp145, a non active-site residue, demonstrated functional role to retain enzyme activity. The enzyme was localized in cytosolic fraction of M. tuberculosis H37Rv. The enzyme was able to synthesize ester of butyric acid, methyl butyrate, in presence of methanol. LipN was able to hydrolyze 4-hydroxyphenylacetate
LipN(Rv2970c)属于结核分枝杆菌H37Rv的Lip家族,与人激素敏感性脂肪酶同源。该酶表现出对短碳链底物的偏爱,该底物在45℃/ pH 8.0下具有最佳活性,在pH 6.0至9.0之间具有稳定性。该酶的比活为217 U / mg蛋白,pNP丁酸酯为底物。将三丁酸甘油酯水解为二丁酸和一丁酸。确认该酶的活性位点残基为Ser216,Asp316和His346。Tetrahydrolipstatin,RHC-80267和N-溴代琥珀酰亚胺可完全抑制LipN酶的活性。有趣的是,非活性位点残基Trp145表现出保留酶活性的功能。该酶位于结核分枝杆菌H37Rv的胞质级分中。该酶能够合成丁酸的酯,丁酸甲酯,在甲醇存在下。LipN能够将4-羟基苯乙酸酯水解为对苯二酚。该基因在体外生长条件下不表达,而在结核分枝杆菌H37Ra巨噬细胞感染后6小时观察到了rv2970c基因的表达。在个别体外应激条件下,
Lubricant base oil palm origin
申请人:Choo May Yuen
公开号:US20050119137A1
公开(公告)日:2005-06-02
A cost effective and less energy demanding method of producing ester oils or lubricant base oils, particularly fatty monoesters and fatty polyol esters, by esterifying palm fatty acid, which is abundant from the fat splitting process, with a monohydric alcohol or polyhydric alcohol in the presence of an acid catalyst at elevated temperature wherein an azeotroping agent, particularly toluene, is used to facilitate continuous removal by distillation, of water formed as a by-product during the esterification reaction. The esterification reaction is completed within 5 hours and palm fatty esters as produced with the current method exhibit comparable lubricity and biodegradability.
It is an object of the present invention to synthesize a carba cyclic phosphatidic acid derivative having a novel structure by substituting O at position sn-2 of the glycerol skeleton with CH
2
, and study the action of the obtained derivative to suppress cancer cell invasion. The present invention provides a compound represented by the following formula (I):
wherein R represents a linear or branched alkyl group containing 1 to 30 carbon atoms, a linear or branched alkenyl group containing 2 to 30 carbon atoms, or a linear or branched alkynyl group containing 2 to 30 carbon atoms, wherein these groups may comprise a cycloalkane ring or aromatic ring; and M represents a hydrogen atom or counter cation.
There is disclosed a method for providing for the coexpression of N-myristoyltransferase and a protein substrate for said N-myristoyltransferase in E. coli comprising introducing into E. coli a dual plasmid system comprising (A) the isopropyl-.beta.-D-thiogalactopyranoside-inducible tac promoter, the g10-L ribosome binding site, a NMT gene, the kanamycin resistance gene and the p15A origin of replication in operable sequence and (B) the recA promoter, the g10-L ribosome binding site, a mammalian gene, the ampicillin resistance gene and the Col E1 origin of replication in operable sequence. This allows production of mammalian N-myristoylproteins or proteins containing covalently linked analogs of myristate with altered physical-chemical properties.
A cost effective and less energy demanding method of producing ester oils or lubricant base oils, particularly fatty monoesters and fatty polyol esters, by esterifying palm fatty acid, which is abundant from the fat splitting process, with a monohydric alcohol or polyhydric alcohol in the presence of an acid catalyst at elevated temperature wherein an azeotroping agent, particularly toluene, is used to facilitate continuous removal by distillation, of water formed as a by-product during the esterification reaction. The esterification reaction is completed within 5 hours and palm fatty esters as produced with the current method exhibit comparable lubricity and biodegradability.