Comparison of Protein N-Homocysteinylation in Rat Plasma under Elevated Homocysteine Using a Specific Chemical Labeling Method.
Elevated blood concentrations of homocysteine have been well established as a risk factor for cardiovascular diseases and neuropsychiatric diseases, yet the etiologic relationship of homocysteine to these disorders remains poorly understood. Protein N-homocysteinylation has been hypothesized as a contributing factor; however, it has not been examined globally owing to the lack of suitable detection methods. We recently developed a selective chemical method to label N-homocysteinylated proteins with a biotin-aldehyde tag followed by Western blotting analysis, which was further optimized in this study. We then investigated the variation of protein N-homocysteinylation in plasma from rats on a vitamin B12 deficient diet. Elevated "total homocysteine" concentrations were determined in rats with a vitamin B12 deficient diet. Correspondingly, overall levels of plasma protein N-homocysteinylation displayed an increased trend, and furthermore, more pronounced and statistically significant changes (e.g., 1.8-fold, p-value: 0.03) were observed for some individual protein bands. Our results suggest that, as expected, a general metabolic correlation exists between "total homocysteine" and N-homocysteinylation, although other factors are involved in homocysteine/homocysteine thiolactone metabolism, such as the transsulfuration of homocysteine by cystathionine β-synthase or the hydrolysis of homocysteine thiolactone by paraoxonase 1 (PON1), may play more significant or direct roles in determining the level of N-homocysteinylation.
Barnett Institute of Chemical and Biological Analysis, Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA. zangt@mail.med.upenn.edu.
Tianzhu
T
Zang
Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA. Ligi.Paul_Pottenplackel@tufts.edu.
Ligi Paul
LP
Pottenplackel
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. dhandy@rics.bwh.harvard.edu.
Diane E
DE
Handy
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. jloscalzo@partners.org.
Joseph
J
Loscalzo
Barnett Institute of Chemical and Biological Analysis, Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA. daishujia@gmail.com.
Shujia
S
Dai
Department of Pharmaceutical Sciences, Nova Southeastern University, Fort Lauderdale, FL 33314, USA. rdeth@nova.edu.
Richard C
RC
Deth
Barnett Institute of Chemical and Biological Analysis, Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA. z.zhou@northeastern.edu.
Zhaohui Sunny
ZS
Zhou
Barnett Institute of Chemical and Biological Analysis, Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA. jishengma@163.com.|School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China. jishengma@163.com.
Jisheng
J
Ma
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D006710:Homocysteine / Q000097:blood*; D020138:Hyperhomocysteinemia / Q000097:blood*; D010949:Plasma / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D051381:Rats; D014806:Vitamin B 12 Deficiency / Q000097:blood*
D001798:Blood Proteins; D006710:Homocysteine
Western blotting; biotin-aldehyde; cardiovascular disease; hyperhomocysteinemia; neuropsychiatric disease; plasma; protein N-homocysteinylation