1
|
Up-to-date knowledge about analytical methods for homocysteine thiolactone determination in biological samples. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
2
|
The Use of Single Drop Microextraction and Field Amplified Sample Injection for CZE Determination of Homocysteine Thiolactone in Urine. Molecules 2021; 26:molecules26185687. [PMID: 34577158 PMCID: PMC8468900 DOI: 10.3390/molecules26185687] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 12/03/2022] Open
Abstract
Two cheap, simple and reproducible methods for the electrophoretic determination of homocysteine thiolactone (HTL) in human urine have been developed and validated. The first method utilizes off-line single drop microextraction (SDME), whereas the second one uses off-line SDME in combination with field amplified sample injection (FASI). The off-line SDME protocol consists of the following steps: urine dilution with 0.2 mol/L, pH 8.2 phosphate buffer (1:2, v/v), chloroform addition, drop formation and extraction of HTL. The pre-concentration of HTL inside a separation capillary was performed by FASI. For sample separation, the 0.1 mol/L pH 4.75 phosphate buffer served as the background electrolyte, and HTL was detected at 240 nm. A standard fused-silica capillary (effective length 55.5 cm, 75 μm id) and a separation voltage of 21 kV (~99 μA) were used. Electrophoretic separation was completed within 7 min, whereas the LOD and LOQ for HTL were 0.04 and 0.1 μmol/L urine, respectively. The calibration curve in urine was linear in the range of 0.1–0.5 μmol/L, with R2 = 0.9991. The relative standard deviation of the points of the calibration curve varied from 2.4% to 14.9%. The intra- and inter-day precision and recovery were 6.4–10.2% (average 6.0% and 6.7%) and 94.9–102.7% (average 99.7% and 99.5%), respectively. The analytical procedure was successfully applied to the analysis of spiked urine samples obtained from apparently healthy volunteers.
Collapse
|
3
|
Purgat K, Olejarz P, Kośka I, Głowacki R, Kubalczyk P. Determination of homocysteine thiolactone in human urine by capillary zone electrophoresis and single drop microextraction. Anal Biochem 2020; 596:113640. [PMID: 32092290 DOI: 10.1016/j.ab.2020.113640] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 02/18/2020] [Accepted: 02/18/2020] [Indexed: 12/28/2022]
Abstract
A simple, fast, sensitive and reproducible capillary zone electrophoresis (CZE) method with single drop microextraction (SDME) for determination of homocysteine thiolactone (HTL) in human urine has been developed and validated. The method is characterized by good precision, high accuracy, short analysis time and low consumption of reagents. The procedure consists only of few steps: urine sample centrifugation, dilution with phosphate buffer and methanol, chloroform addition onto the top of donor phase, on-line SDME in CE system, sample separation by CZE and ultraviolet detection of HTL at 240 nm. The background electrolyte was 0.1 M pH 4.75 phosphate buffer. Effective separation was achieved within 6.04 min under the separation voltage of 24 kV (~110 μA). The LOQ and LOD for HTL were 50 and 25 nM urine, respectively. The calibration curve in urine showed linearity in the range of 50-200 nM, with R2 0.9995. The intra- and inter-day precision and recovery were 4.0-14.5% (average 8.7% and 9.3%) and 92.7-115.5% (average 103.6% and 104.8%), respectively. The procedure was successfully applied to analysis of urine samples.
Collapse
Affiliation(s)
- Krystian Purgat
- University of Lodz, Faculty of Chemistry, Department of Environmental Chemistry, Poland
| | - Patrycja Olejarz
- University of Lodz, Faculty of Chemistry, Department of Environmental Chemistry, Poland
| | - Izabella Kośka
- University of Lodz, Faculty of Chemistry, Department of Environmental Chemistry, Poland; University of Lodz, Doctoral School of Exact and Natural Sciences, Poland
| | - Rafał Głowacki
- University of Lodz, Faculty of Chemistry, Department of Environmental Chemistry, Poland
| | - Paweł Kubalczyk
- University of Lodz, Faculty of Chemistry, Department of Environmental Chemistry, Poland.
| |
Collapse
|
4
|
Borowczyk K, Olejarz P, Chwatko G, Szylberg M, Głowacki R. A Simplified Method for Simultaneous Determination of α-Lipoic Acid and Low-Molecular-Mass Thiols in Human Plasma. Int J Mol Sci 2020; 21:ijms21031049. [PMID: 32033303 PMCID: PMC7037620 DOI: 10.3390/ijms21031049] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 12/12/2022] Open
Abstract
α-Lipoic acid, glutathione, cysteine, and cysteinylglycine can be applied as therapeutic agents in civilization diseases such as diabetes mellitus, cardiovascular diseases, and cancers. On the other hand, a higher concentration of homocysteine can result in health problems and has been indicated as an independent risk factor for cardiovascular disease and accelerated atherosclerosis. Here, the first simplified HPLC-UV assay that enables simultaneous determination of α-lipoic acid and low-molecular-mass thiols in plasma, reduces the number of steps, shortens the total time of sample preparation, and limits the amount of single-use polypropylene laboratory materials is described. The assay is based on reversed-phase high performance liquid chromatography with UV detection and simultaneous reduction of disulfide bound with tris(2-carboxyethyl)phosphine and the selective pre-column derivatization of the thiol group with 1-benzyl-2-chloropyridinium bromide. Linearity in the detector responses for plasma samples were observed in ranges: 0.12-5.0 nmol mL-1 for α-lipoic acid; 2.0-20.0 nmol mL-1 for glutathione, cysteinylglycine, and homocysteine; and 40.0-400.0 for cysteine. The LODs for α-lipoic acid and low-molecular-mass thiols were 0.08 and 0.12 nmol mL-1, respectively, while LOQs were 0.12 and 0.16 nmol mL-1, respectively. The usefulness of the proposed method has been proven by its application to real samples.
Collapse
Affiliation(s)
- Kamila Borowczyk
- Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 163, 90-236 Łódź, Poland; (P.O.); (G.C.); (R.G.)
- Correspondence: ; Tel.: +48-426-3558-44; Fax: +48-4263-558-41
| | - Patrycja Olejarz
- Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 163, 90-236 Łódź, Poland; (P.O.); (G.C.); (R.G.)
| | - Grażyna Chwatko
- Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 163, 90-236 Łódź, Poland; (P.O.); (G.C.); (R.G.)
| | - Marcin Szylberg
- Rehabilitation Center “Kraszewski”, Kraszewskiego 7/9, 93-161 Łódź, Poland;
| | - Rafał Głowacki
- Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 163, 90-236 Łódź, Poland; (P.O.); (G.C.); (R.G.)
| |
Collapse
|
5
|
Jakubowski H. Homocysteine Modification in Protein Structure/Function and Human Disease. Physiol Rev 2019; 99:555-604. [PMID: 30427275 DOI: 10.1152/physrev.00003.2018] [Citation(s) in RCA: 152] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epidemiological studies established that elevated homocysteine, an important intermediate in folate, vitamin B12, and one carbon metabolism, is associated with poor health, including heart and brain diseases. Earlier studies show that patients with severe hyperhomocysteinemia, first identified in the 1960s, exhibit neurological and cardiovascular abnormalities and premature death due to vascular complications. Although homocysteine is considered to be a nonprotein amino acid, studies over the past 2 decades have led to discoveries of protein-related homocysteine metabolism and mechanisms by which homocysteine can become a component of proteins. Homocysteine-containing proteins lose their biological function and acquire cytotoxic, proinflammatory, proatherothrombotic, and proneuropathic properties, which can account for the various disease phenotypes associated with hyperhomocysteinemia. This review describes mechanisms by which hyperhomocysteinemia affects cellular proteostasis, provides a comprehensive account of the biological chemistry of homocysteine-containing proteins, and discusses pathophysiological consequences and clinical implications of their formation.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, International Center for Public Health , Newark, New Jersey ; and Department of Biochemistry and Biotechnology, Poznań University of Life Sciences , Poznań , Poland
| |
Collapse
|
6
|
Azad MAK, Huang P, Liu G, Ren W, Teklebrh T, Yan W, Zhou X, Yin Y. Hyperhomocysteinemia and cardiovascular disease in animal model. Amino Acids 2017; 50:3-9. [DOI: 10.1007/s00726-017-2503-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/04/2017] [Indexed: 01/16/2023]
|
7
|
Szlauer A, Mielimonka A, Głowacki R, Borowczyk K, Stachniuk J, Undas A. Protein N-linked homocysteine is associated with recurrence of venous thromboembolism. Thromb Res 2015; 136:911-6. [PMID: 26371408 DOI: 10.1016/j.thromres.2015.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 01/26/2023]
Abstract
BACKGROUND Recently, protein N-linked homocysteine (Hcy) has been measured in healthy subjects and patients with marked hyperhomocysteinemia. Since elevated total Hcy (tHcy) levels are associated with increased risk of venous thromboembolism (VTE), we aimed to investigate protein N-linked Hcy levels in patients with VTE. METHODS We studied 200 consecutive patients with VTE (89 men, 111 women, aged from 17 to 83 years), including 57 subjects with a subsequent episode of VTE (recurrent VTE) during 24 months of follow-up. Protein N-linked Hcy was assayed using high-performance liquid chromatography with an on-column derivatization with o-phthaldialdehyde and fluorescence detection. RESULTS The median protein N-linked Hcy was 1.404 μM (interquartile range [IQR] 0.859-2.066), while the median tHcy (IQR) was 9.1 μM (6.8-11.2). In the whole group protein N-linked Hcy correlated only with C-reactive protein (CRP; r = 0.44, p < 0.0001). In patients with recurrent VTE protein N-linked Hcy correlated with C-reactive protein (r = 0.43, p < 0.0001), tHcy (r = 0.42, p = 0.001) and age (r = 0.32, p = 0.014), but not with thrombophilia, unprovoked VTE or the current anticoagulation. Hyperhomocysteinemia, defined as tHcy ≥ 15 μM (n = 14.7%), was not associated with higher protein N-linked Hcy. Patients with recurrent VTE had higher levels of protein N-linked Hcy compared to those who experienced a single episode of VTE (1.553 μM, 1.157-2.445 vs. 1.27 μM, 0.826-1.884; p = 0.002). Multiple regression adjusted for potential confounders showed that the only independent predictor of protein N-linked Hcy in the upper quartile was CRP > 3mg/L (odds ratio 3.04, 95% confidence interval 2.12-4.36, p < 0.0001). CONCLUSION Elevated protein N-linked Hcy concentrations, indicating enhanced protein homocysteinylation in vivo, characterize patients with recurrent VTE and this phenomenon is associated with enhanced inflammatory state.
Collapse
Affiliation(s)
- Anastazja Szlauer
- Students' Scientific Association, Jagiellonian University Medical College, Krakow, Poland
| | - Aleksandra Mielimonka
- Students' Scientific Association, Jagiellonian University Medical College, Krakow, Poland
| | - Rafał Głowacki
- Department of Environmental Chemistry, University of Lodz, Lodz, Poland
| | - Kamila Borowczyk
- Department of Environmental Chemistry, University of Lodz, Lodz, Poland
| | - Justyna Stachniuk
- Department of Environmental Chemistry, University of Lodz, Lodz, Poland
| | - Anetta Undas
- Institute of Cardiology, Jagiellonian University Medical College, John Paul II Hospital, Krakow, Poland.
| |
Collapse
|
8
|
Głowacki R, Borowczyk K, Bald E. Determination of Nɛ-homocysteinyl-lysine and γ-glutamylcysteine in plasma by liquid chromatography with UV-detection. JOURNAL OF ANALYTICAL CHEMISTRY 2014. [DOI: 10.1134/s1061934814060082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
9
|
Suszyńska-Zajczyk J, Wróblewski J, Utyro O, Luczak M, Marczak L, Jakubowski H. Bleomycin hydrolase and hyperhomocysteinemia modulate the expression of mouse proteins involved in liver homeostasis. Amino Acids 2014; 46:1471-80. [PMID: 24633403 DOI: 10.1007/s00726-014-1712-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 02/21/2014] [Indexed: 12/13/2022]
Abstract
The liver is the major contributor to homocysteine (Hcy) metabolism and fatty liver disease is associated with hyperhomocysteinemia. Bleomycin hydrolase (Blmh) is an aminohydrolase that also participates in Hcy metabolism by hydrolyzing Hcy-thiolactone. To gain insight into hepatic functions of Blmh, we analyzed the liver proteome of Blmh(-/-) and Blmh(+/+) mice in the absence and presence of diet-induced (high methionine) hyperhomocysteinemia using 2D IEF/SDS-PAGE gel electrophoresis and MALDI-TOF mass spectrometry. We identified eleven liver proteins whose expression was significantly altered as a result of the Blmh gene inactivation. The differential expression (Blmh(-/-) vs. Blmh(+/+)) of four liver proteins was lower, of two proteins was higher, and was further modified in mice fed with a hyperhomocysteinemic high-Met diet. The down-regulated proteins are involved in lipoprotein metabolism (ApoA1, ApoE), antigen processing (Psme1), energy metabolism (Atp5h, Gamt), methylglyoxal detoxification (Glo1), oxidative stress response (Sod1), and inactivation of catecholamine neurotransmitters (Comt). The two up-regulated proteins are involved in nitric oxide generation (Ddah1) and xenobiotic detoxification (Sult1c1). We also found that livers of Blmh(-/-) mice expressed a novel variant of glyoxalase domain-containing protein 4 (Glod4) by a post-transcriptional mechanism. Our findings suggest that Blmh interacts with diverse cellular processes-from lipoprotein metabolism, nitric oxide regulation, antigen processing, and energy metabolism to detoxification and antioxidant defenses-that are essential for liver homeostasis and that modulation of these interactions by hyperhomocysteinemia underlies the involvement of Hcy in fatty liver disease.
Collapse
|
10
|
Jakubowski H. The Mechanism and Consequences of Homocysteine Incorporation Into Protein in Humans. PHOSPHORUS SULFUR 2013. [DOI: 10.1080/10426507.2012.736104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hieronim Jakubowski
- a Department of Microbiology & Molecular Genetics, UMDNJ-New Jersey Medical School , International Center for Public Health , Newark , NJ , USA
- b Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, and Department of Biochemistry and Biotechnology , University of Life Sciences , Poznań , Poland
| |
Collapse
|
11
|
Malinowska J, Tomczynska M, Olas B. Changes of blood platelet adhesion to collagen and fibrinogen induced by homocysteine and its thiolactone. Clin Biochem 2012; 45:1225-8. [DOI: 10.1016/j.clinbiochem.2012.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 05/10/2012] [Accepted: 05/12/2012] [Indexed: 10/28/2022]
|
12
|
Mazur P, Kozynacka A, Durajski L, Głowacki R, Pfitzner R, Fijorek K, Sadowski J, Undas A. Nɛ-homocysteinyl-lysine isopeptide is associated with progression of peripheral artery disease in patients treated with folic acid. Eur J Vasc Endovasc Surg 2012; 43:588-93. [PMID: 22436266 DOI: 10.1016/j.ejvs.2012.02.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 02/20/2012] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Folic acid (FA) administration can reduce plasma total homocysteine (tHcy); however, it fails to decrease cardiovascular events and progression of peripheral artery disease (PAD). Nɛ-homocysteinyl-lysine isopeptide (Nɛ-Hcy-Lys) is formed during catabolism of homocysteinylated proteins. We sought to investigate factors that determine the presence of Nɛ-Hcy-Lys in PAD patients with hyperhomocysteinemia receiving FA. PATIENTS AND METHODS We studied 131 consecutive PAD patients with tHcy > 15 μmol l(-1) taking FA 0.4 mg d(-1) for 12 months. Serum Nɛ-Hcy-Lys was determined by high-performance liquid chromatography (HPLC). We also measured interleukin-6 (IL-6), plasminogen activator inhibitor-1 (PAI-1), asymmetric dimethylarginine (ADMA) and 8-iso-prostaglandin F(2α) (8-iso-PGF(2α)). RESULTS FA administration resulted in a 70.5% decrease in tHcy (p < 0.0001). However, serum Nɛ-Hcy-Lys was detectable in 28 (21.4%) patients on FA who were more frequently current smokers and survivors of ischaemic stroke (p < 0.001). They had higher tHcy by 46.0%, PAI-1 by 51.7%, 8-iso-PGF(2α) by 59.1% and ADMA by 26.4% (all, p < 0.0001). The presence of Nɛ-Hcy-Lys was associated with lower ankle-brachial index (ABI) values (p < 0.001) and higher prevalence of cardiovascular events (p < 0.001) following therapy. CONCLUSION The presence of Nɛ-Hcy-Lys in one-fifth of hyperhomocysteinemic individuals with PAD despite FA treatment is associated with progression of PAD and with increased ADMA formation, oxidative stress and hypofibrinolysis.
Collapse
Affiliation(s)
- P Mazur
- Institute of Cardiology, Jagiellonian University Medical College, Krakow, Poland
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Yilmaz N. Relationship between paraoxonase and homocysteine: crossroads of oxidative diseases. Arch Med Sci 2012; 8:138-53. [PMID: 22457688 PMCID: PMC3309450 DOI: 10.5114/aoms.2012.27294] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 02/17/2011] [Accepted: 04/07/2011] [Indexed: 01/14/2023] Open
Abstract
Homocysteine (Hcy) is an accepted independent risk factor for several major pathologies including cardiovascular disease, birth defects, osteoporosis, Alzheimer's disease, and renal failure. Interestingly, many of the pathologies associated with homocysteine are also linked to oxidative stress. The enzyme paraoxonase (PON1) - so named because of its ability to hydrolyse the toxic metabolite of parathion, paraoxon - was also shown early after its identification to manifest arylesterase activity. Although the preferred endogenous substrate of PON1 remains unknown, lactones comprise one possible candidate class. Homocysteine-thiolactone can be disposed of by enzymatic hydrolysis by the serum Hcy-thiolactonase/paraoxonase carried on high-density lipoprotein (HDL). In this review, Hcy and the PON1 enzyme family were scrutinized from different points of view in the literature and the recent articles on these subjects were examined to determine whether these two molecular groups are related to each other like a coin with two different sides, so close and yet so different and so opposite.
Collapse
Affiliation(s)
- Necat Yilmaz
- Central Laboratories of Antalya Education and Research Hospital of Ministry of Health, Antalya, Turkey
| |
Collapse
|
14
|
Borowczyk K, Tisończyk J, Jakubowski H. Metabolism and neurotoxicity of homocysteine thiolactone in mice: protective role of bleomycin hydrolase. Amino Acids 2012; 43:1339-48. [PMID: 22227865 DOI: 10.1007/s00726-011-1207-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 12/21/2011] [Indexed: 10/14/2022]
Abstract
Genetic or nutritional disorders in homocysteine (Hcy) metabolism elevate Hcy-thiolactone and cause heart and brain diseases. Hcy-thiolactone has been implicated in these diseases because it has the ability to modify protein lysine residues and generate toxic N-Hcy-proteins with auto-immunogenic, pro-thrombotic, and amyloidogenic properties. Bleomycin hydrolase (Blmh) has the ability to hydrolyze L-Hcy-thiolactone (but not D-Hcy-thiolactone) to Hcy in vitro, but whether this reflects a physiological function has been unknown. Here, we show that Blmh (-/-) mice excreted in urine 1.8-fold more Hcy-thiolactone than wild-type Blmh (+/+) animals (P = 0.02). Hcy-thiolactone was elevated 2.3-fold in brains (P = 0.004) and 2.0-fold in kidneys (P = 0.047) of Blmh (-/-) mice relative to Blmh (+/+) animals. Plasma N-Hcy-protein was elevated in Blmh (-/-) mice fed a normal (2.3-fold, P < 0.001) or hyperhomocysteinemic diet (1.5-fold, P < 0.001), compared with Blmh (+/+) animals. More intraperitoneally injected L-Hcy-thiolactone was recovered in plasma in Blmh (-/-) mice than in wild-type Blmh (+/+) animals (83.1 vs. 39.3 μM, P < 0.0001). In Blmh (+/+) mice injected intraperitoneally with D-Hcy-thiolactone, D,L-Hcy-thiolactone, or L-Hcy-thiolactone, 88, 47, or 6.3%, respectively, of the injected dose was recovered in plasma. The incidence of seizures induced by L-Hcy-thiolactone injections (3,700 nmol/g body weight) was higher in Blmh (-/-) than in Blmh (+/+) mice (93.8 vs. 29.5%, P < 0.001). Using the Blmh null mice, we provide the first direct evidence that a specific Hcy metabolite, Hcy-thiolactone, rather than Hcy itself, is neurotoxic in vivo. Taken together, our findings indicate that Blmh protects mice against L-Hcy-thiolactone toxicity by metabolizing it to Hcy and suggest a mechanism by which Blmh might protect against neurodegeneration associated with hyperhomocysteinemia and Alzheimer's disease.
Collapse
Affiliation(s)
- Kamila Borowczyk
- Department of Microbiology and Molecular Genetics, International Center for Public Health, UMDNJ-New Jersey Medical School, 225 Warren Street, Newark, NJ 07101, USA
| | | | | |
Collapse
|
15
|
Jakubowski H, Głowacki R. Chemical biology of homocysteine thiolactone and related metabolites. Adv Clin Chem 2011; 55:81-103. [PMID: 22126025 DOI: 10.1016/b978-0-12-387042-1.00005-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Protein-related homocysteine (Hcy) metabolism produces Hcy-thiolactone, N-Hcy-protein, and N epsilon-homocysteinyl-lysine (N epsilon-Hcy-Lys). Hcy-thiolactone is generated in an error-editing reaction in protein biosynthesis when Hcy is erroneously selected in place of methionine by methionyl-tRNA synthetase. Hcy-thiolactone, an intramolecular thioester, is chemically reactive and forms isopeptide bonds with protein lysine residues in a process called N-homocysteinylation, which impairs or alters the protein's biological function. The resulting protein damage is exacerbated by a thiyl radical-mediated oxidation. N-Hcy-proteins undergo structural changes leading to aggregation and amyloid formation. These structural changes generate proteins, which are toxic and which induce an autoimmune response. Proteolytic degradation of N-Hcy-proteins generates N epsilon-Hcy-Lys. Levels of Hcy-thiolactone, N-Hcy-protein, and N epsilon-Hcy-Lys increase under pathological conditions in humans and mice and have been linked to cardiovascular and brain disorders. This chapter reviews fundamental biological chemistry of Hcy-thiolactone, N-Hcy-protein, and N epsilon-Hcy-Lys and discusses their clinical significance.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, International Center for Public Health, Newark, New Jersey, USA.
| | | |
Collapse
|
16
|
Jakubowski H. Quality control in tRNA charging. WILEY INTERDISCIPLINARY REVIEWS-RNA 2011; 3:295-310. [PMID: 22095844 DOI: 10.1002/wrna.122] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Faithful translation of the genetic code during protein synthesis is fundamental to the growth, development, and function of living organisms. Aminoacyl-tRNA synthetases (AARSs), which define the genetic code by correctly pairing amino acids with their cognate tRNAs, are responsible for 'quality control' in the flow of information from a gene to a protein. When differences in binding energies of amino acids to an AARS are inadequate, editing is used to achieve high selectivity. Editing occurs at the synthetic active site by hydrolysis of noncognate aminoacyl-adenylates (pretransfer editing) and at a dedicated editing site located in a separate domain by deacylation of mischarged aminoacyl-tRNA (posttransfer editing). Access of nonprotein amino acids, such as homocysteine or ornithine, to the genetic code is prevented by the editing function of AARSs, which functionally partitions amino acids present in living cells into protein and nonprotein amino acids. Continuous editing is part of the tRNA aminoacylation process in living organisms from bacteria to human beings. Preventing mistranslation by the clearance of misactivated amino acids is crucial to cellular homeostasis and has a role in etiology of disease. Although there is a strong selective pressure to minimize mistranslation, some organisms possess error-prone AARSs that cause mistranslation. Elevated levels of mistranslation and the synthesis of statistical proteins can be beneficial for pathogens by increasing phenotypic variation essential for the evasion of host defenses.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, International Center for Public Health, Newark, NJ, USA.
| |
Collapse
|
17
|
Ultraviolet derivatization of low-molecular-mass thiols for high performance liquid chromatography and capillary electrophoresis analysis. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:1290-307. [DOI: 10.1016/j.jchromb.2010.10.035] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 10/20/2010] [Accepted: 10/28/2010] [Indexed: 11/30/2022]
|