Camel Liver Esterase （LE） was isolated through five consecutive steps： Extraction with Tris/HCl buffer, pH 8, precipitation with ammonium sulfate, affinity chromatography on Affi-gel-butyric acid and on Affi-gel-ol...Camel Liver Esterase （LE） was isolated through five consecutive steps： Extraction with Tris/HCl buffer, pH 8, precipitation with ammonium sulfate, affinity chromatography on Affi-gel-butyric acid and on Affi-gel-oleic acid, and preparative polyacrylamide gel electrophoresis （PAGE）. The Km values were found as： methyl butyrate （8.3 mM）, α-naphthyl acetate （3.65 mM）, 13-naphthyl myristate （66.7 mM）, p-nitrophenyl acetate （0.29 mM）, and phenyl acetate （5.26 mM）. The Ki of LE inhibition by bis（4-nitrophenyl） phosphate was 7.9 p.M, and 58 μM by phenyl-methyl-sulfonyl fluoride. The inhibition by these inhibitors is irreversible. p-Hydroxymercuribenzoate or ethylenediamine-tetra-acetic acid did not inhibit the enzyme. LE showed a dimeric structure with molecular weight of 129 kD. The energy of activation of LE was 15.0, 5.5 and 10.75 Kcal, using the substrates： a-naphthyl acetate, p-nitrophenyl acetate, and methyl butyrate, respectively. The optimal pH for LE was between 8 and 10. The N-terminus was found as aspartic acid. The percentage of glycine residues （13.3%） was the highest whereas the percentage of cysteine residues （0.68%） was the lowest in LE. Amino acid composition shows that LE has -50% of its histidine residues as N-methylhistidines.展开更多
In this study, mitochondrial 16S rRNA sequences of snow leopard, gray wolf, domestic horse and Bactrian camel inhabited or domesticated in Mongolian territory were obtained by using polymerase chain reaction （PCR） b...In this study, mitochondrial 16S rRNA sequences of snow leopard, gray wolf, domestic horse and Bactrian camel inhabited or domesticated in Mongolian territory were obtained by using polymerase chain reaction （PCR） based on universal primers for 16S rRNA （F-5＇-AACGAGCCTGGTGATA-3＇ and R-5＇-CTCCGGTCTGAACTCAGATCACGTA-3＇）. The 16S rRNA sequence was 1,048 bp to 1,086 bp in length, and each sequence was compared to other related species （Felidae, Camelidae, Equidae and Canidae） by using NCBI Basic Local Alignment Search Tool （BLAST）. Results showed that sequences were highly similar to sequences in GenBank database （93%-99%）. Then phylogenetic analysis was performed based on about 1,100 bp sequence of 16S rRNA for Panthera uncia, Canis lupus, Equus caballus, Camelus bactrianus and other related species. The result revealed that P. uncia and P. leo were sister species, C. bactrianus and C. ferus were more closely related species, and wolf and dog were the almost similar species. This finding could be important for designing species specific primers for PCR based analysis of animal species identification and forensic veterinary medicine.展开更多
文摘Camel Liver Esterase （LE） was isolated through five consecutive steps： Extraction with Tris/HCl buffer, pH 8, precipitation with ammonium sulfate, affinity chromatography on Affi-gel-butyric acid and on Affi-gel-oleic acid, and preparative polyacrylamide gel electrophoresis （PAGE）. The Km values were found as： methyl butyrate （8.3 mM）, α-naphthyl acetate （3.65 mM）, 13-naphthyl myristate （66.7 mM）, p-nitrophenyl acetate （0.29 mM）, and phenyl acetate （5.26 mM）. The Ki of LE inhibition by bis（4-nitrophenyl） phosphate was 7.9 p.M, and 58 μM by phenyl-methyl-sulfonyl fluoride. The inhibition by these inhibitors is irreversible. p-Hydroxymercuribenzoate or ethylenediamine-tetra-acetic acid did not inhibit the enzyme. LE showed a dimeric structure with molecular weight of 129 kD. The energy of activation of LE was 15.0, 5.5 and 10.75 Kcal, using the substrates： a-naphthyl acetate, p-nitrophenyl acetate, and methyl butyrate, respectively. The optimal pH for LE was between 8 and 10. The N-terminus was found as aspartic acid. The percentage of glycine residues （13.3%） was the highest whereas the percentage of cysteine residues （0.68%） was the lowest in LE. Amino acid composition shows that LE has -50% of its histidine residues as N-methylhistidines.
文摘In this study, mitochondrial 16S rRNA sequences of snow leopard, gray wolf, domestic horse and Bactrian camel inhabited or domesticated in Mongolian territory were obtained by using polymerase chain reaction （PCR） based on universal primers for 16S rRNA （F-5＇-AACGAGCCTGGTGATA-3＇ and R-5＇-CTCCGGTCTGAACTCAGATCACGTA-3＇）. The 16S rRNA sequence was 1,048 bp to 1,086 bp in length, and each sequence was compared to other related species （Felidae, Camelidae, Equidae and Canidae） by using NCBI Basic Local Alignment Search Tool （BLAST）. Results showed that sequences were highly similar to sequences in GenBank database （93%-99%）. Then phylogenetic analysis was performed based on about 1,100 bp sequence of 16S rRNA for Panthera uncia, Canis lupus, Equus caballus, Camelus bactrianus and other related species. The result revealed that P. uncia and P. leo were sister species, C. bactrianus and C. ferus were more closely related species, and wolf and dog were the almost similar species. This finding could be important for designing species specific primers for PCR based analysis of animal species identification and forensic veterinary medicine.
