• Biomolecules & Therapeutics
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• 제1권1호
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• pp.65-70
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• 1993

Trimethyllysine(TML) is in vivo released when the methylated proteins are subjected to metabolic breakdown and may serve as a precursor for the biosynthesis of carnitine. It was also demonstrated that high concentration of free TML was observed in red blood cell. Therefore, in order to study the functions of TML in RBC we determined the concentration of TML and carnitine in RBC of hyperthyroid and hypothyroid rats and the following results were observed. 1)In hyperthyroid rats, the concentrations of TML, free carnitine and acylcarnitine in RBC were increased. 2) In hypothyroid rats, the concentrations of TML and acylcarnitine were increased but free carnitine was sharply decreased. 3) In diabetic rats, TML and free carnitine both were inclined to decrease, but not significant statistically. 4) In fasting rats, TML was not changed but free carnitine was sharply decreased. These results suggest that TML in RBC is not directly related to biosynthesis of carnitine.

• Preventive Nutrition and Food Science
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• 제3권3호
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• pp.251-255
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• 1998

Rat testis known to contain all of the enzymes required for carnitine biosynthesis also contains high concentration of calmodulin, a protein which may or may not contain trimethyllysine, the major substrate in carnitine biosynthesis. The purpose of this study was to investigate the levels of carnitine and the state of calmodulin N-methylation in rat testes, and to discuss the possibility of the involvement of calmodulin incarnitine biosynthesis. Nonesterified carnitine , acid soluble acyl carnitine, and acid insoluble acyl carnitine of ra tests were 273 nmole, 62nmole, and 4 nmole/g tissue, respectively. Total carnitine level was 339 nmole/g testes tissue. Calmodulin purified from rat tests was assayed for methylation potential using N-methyltransferase from the rat testes. Rat testes calmodulin showed no 3H-methyl incorporation indicating that the calmodulin was trimethylated already by endogenous calmodulin N-methyltransferase. Amino acid composition analysis revealed that the rat testes calmodulin containd one mole of trimethyllysine per mole of calmodulin. These data suggest that testes calmodulin could provide the trimethyllysine needed for the synthesis of carnitine in the rat tests.

• Archives of Pharmacal Research
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• 제9권1호
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• pp.15-18
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• 1986

Various naturally occuring methylated amino acid derivatives were resolved on high performance liquid chromatography (HPLC), using o-phthadialdehyde as a fluorogenic reagent. We separated .$\varepsilon$-N-monomethyllysine, $\varepsilon$-N- dimethyllysine, and $\varepsilon$-N-acetyllysine from lysine derivatives. $N^{G}$-Monomethylarginine and $N^{G}$-dimethylarginine were separated from arginine derivatives. However, $\varepsilon$-N-monomethyllsine and $\varepsilon$-N-trimethyllysine, $N^{G}$, $N^{G}$-dimethylarginine and $N^{G}$, $N^{G}$-dimethylarginine were not resolved under the conditions employed. S-Methylmethionine, S-methylcysteine, and 1-N-methylhistidine or 3-N-methylhistidine were clearly separated from their reference amino acids, even though 1-N-methyl-and 3-N-methylhistidine coul not be separated.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.505.1-505
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• 1986

The gene for iso-1-cytochrome c for Saccharomyces cerevisiae was recloned into a pSP65 vector containing an active bacteriophage SP6 promoter. The iso-1-cytochrome c gene was cloned as an 856 bp Xho 1-Hind III fragment. When the resulting plasmid was digested at the Hind 111 site 279 bases downstream from the termination codon of the gene and transcribed in vitro using SP6 RNA polymerase, full length transcripts were produced. The SP6 iso-1-cytochrome c mRNA was translated using a rabbit reticulocyte lysate system and the protein products analyzed on SDS polyacrylamide gels. One major band was detected by autofluorography. This band was found to have a molecular weight of 12,000 Da and coincided with the Coomassie staining band of apocytochrome c from S. cerebisiae. The product was also shown to be identical with that of standard yeast apocytochrome c on an isoelectric focusing gel. The in vitro synthesized iso-a-cytochrome c was methylated by adding partially purified S-adenosyl-L-methionine . protein-lysine N-methyltransferase (Protein methylase III; EC 2.1.1.43) from S. cerevisiae along with S-adenosyl-L-methionine to the in vitro translation mixtures. The methylation was shown to be inhibited by the addition of the methylase inhibitor S-adenosyl-L-homocysteine or the protein synthesis inhibitor pu omycin. The methyl derivatives in the protein were identified as $\varepsilon$-N-mono, di and trimethyllysine by amino acid analysis. The molar ratio of methyl groups incorporated to that of cytochrome c molecules synthesized showed that 23% of the translated cytochrome c molecules were methylated by protein methylase III.