Incorporation of human growth hormone-2 into proteoliposome enhances tissue regeneration with anti-oxidant and anti-senescence activities.
Human growth hormone-2 (GH-2) is a 191-amino-acid protein also known as human placental hormone. During pregnancy, continuous secretion of GH-2 appears to have important implications for physiological adjustment to gestation, especially in controlling levels of maternal insulin-like growth factor 1. To compare the physiological activity of GH-2 between lipid-free and lipid-bound states, GH-2 was expressed and incorporated into proteoliposome. GH-2 was expressed and purified using a pET28(a)-GH-2 vector in an Escherichia coli system. Purified GH-2 was then characterized and synthesized into reconstituted high-density lipoprotein (rHDL). The expression yield of GH-2 was 20-30 mg by BL21 (DE3) cells in 1 liter of Luria-Bertani broth. Purified GH-2 of at least 98% purity (23 kDa) was incorporated into rHDL with human apolipoprotein A-I (ApoA-I) and palmitoyloleoyl phosphatidylcholine (POPC) at a 1:1:95 (GH-2:ApoA-I:POPC) molar ratio. Structural analysis revealed that GH-2 had a 44% α-helix content and a wavelength maximum fluorescence (WMF) of 349 nm in a lipid-free state. In a lipid-bound state, the WMF of GH-2 was ∼4 nm blue-shifted (345 nm), with 50% of α-helix content. The lipid-bound GH-2 showed enhanced anti-atherosclerotic activity and anti-senescence activity with inhibition of fructose-mediated glycation. A fin regeneration experiment using zebrafish (17 weeks old, n=9) showed that lipid-bound GH-2 enhanced regeneration efficiency by 44% compared to native GH-2 (in the lipid-free state) without any notable side effects. GH-2 has anti-oxidant activity to enhance tissue regeneration as well as to exert anti-diabetic activity. Incorporation of GH-2 into rHDL can enhance structural stability and tissue regeneration efficiency in vertebrate models, indicating a synergetic effect between GH-2 and ApoA-I in rHDL.
1 School of Biotechnology, Yeungnam University , Gyeongsan, Republic of Korea.
So-Hee
SH
Kim
Eun-Young
EY
Lee
Kyung-Hyun
KH
Cho
D000818:Animals; D000975:Antioxidants / Q000737:chemistry*; D016632:Apolipoprotein A-I / Q000737:chemistry; D016922:Cellular Senescence; D002942:Circular Dichroism; D003720:Densitometry; D004926:Escherichia coli / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008075:Lipoproteins, HDL / Q000737:chemistry; D009000:Monocytes / Q000166:cytology; D010100:Oxygen / Q000737:chemistry; D010587:Phagocytosis; D010713:Phosphatidylcholines / Q000737:chemistry; D010926:Placental Hormones / Q000378:metabolism*; D011247:Pregnancy; D011510:Proteolipids / Q000378:metabolism*; D012038:Regeneration; D013050:Spectrometry, Fluorescence; D015027:Zebrafish
D000975:Antioxidants; D016632:Apolipoprotein A-I; C064980:GH2 protein, human; D008055:Lipids; D008075:Lipoproteins, HDL; D010713:Phosphatidylcholines; D010926:Placental Hormones; D011510:Proteolipids; C020485:proteoliposomes; D013006:Growth Hormone; D010100:Oxygen; C028694:1-palmitoyl-2-oleoylphosphatidylcholine