Cochinin B, a Novel Ribosome-Inactivating Protein from the Seeds of Momordica cochinchinensis

Abstract

Ribosome-inactivating proteins (RIPs) are RNA N-glycosidase enzymes, which are isolated from seeds of many plants. RIPs remove a site-specifically single adenine residue (A 4324 in the case of rat liver ribosome) from the highly conserved sarcin/ricin loop of the 28S rRNA, thus arresting protein synthesis.1,2) RIPs are conventionally classified into three types: type I, II and III based on the conformation of their subunits.2) Type I RIPs are single-chained proteins with enzymatic activity and type II RIPs consist of a catalytic chain linked to a lectin binding chain. Type III RIPs, which are identified mostly in maize and barely, consist of an N-terminal active chain linked to an unrelated C-terminal domain with unknown function.Almost plants of the Cucurbitaceae family are found to contain several type I RIPs in the same species such as Trichosanthin and TAP-29 from Trichosanthes kirilowii, 3,4) Luffin-a and Luffin-b from Luffa cylindrica, 5,6) Bryodin I and Bryodin II from Bryonia dioica, 7) a-Momorcharin and bMomorcharin from Momordica charantia. 8) Type I RIPs are highly basic proteins with pI values of 9-10 and display molecular weight of 26-30 kDa. The proteins from the Cucurbitaceae plants exhibit an array of biological activities including anti-HIV-1, 4,9) immunomodulatory, 10) antiproliferative, 10) deoxyribonuclease 11) and ribonuclease.12) It has recently been described that Momordica cochinchinensis consisted of two isoforms of type I RIPs: namely Momorcochin from root tubers and Momorcochin-S from seeds with molecular mass of approximately 32 kDa and 30 kDa, respectively. 13,14) The proteins are highly basic and have anti-tumor activities. In the present investigation, we reported a novel type I RIPs named as Cochinin B, which was isolated from the seeds of M. cochinchinensis. Cochinin B possessed all typical properties of type I RIPs with a broad range of potent anti-tumor activities. MATERIALS AND METHODSPurification of Cochinin B Ripe seeds of M. cochinchinensis (collected from Nakornpathom, Thailand during April-November 2002) were decorticated in a mortar and a pestle. Endosperm was separated and mixed in ice-cooled 10 mM sodium phosphate buffer pH 6.3 containing 150 mM NaCl and 5 mM EDTA. The mixture was homogenized by a blender and the homogenized sample was filtered through double cheesecloth and centrifuged at 15000 rpm for 30 min at 4°C. After filtering through filter paper, the clear solution was added with 30-60% saturation of ammonium sulfate, stirred for 1 h, and centrifuged at 8000 rpm for 15 min at 4°C. The precipitate was dissolved and dialyzed against 10 mM sodium phosphate buffer pH 6.3 and then applied to a fast protein liquid chromatography (FPLC) system with a SP Sepharose, cation-exchange column (1 cmϫ10 cm), which had previously been equilibrated with the same buffer. The column was initially eluted with the same buffer to remove unadsorbed proteins and subsequently with a linear gradient of 0-1.0 M NaCl in 10 mM sodium phosphate buffer pH 6.3. Fractions that contained 28 k...

Momordica cochinchinensis (L.) Spreng: Aril Extract Prevents Adverse Reproductive Parameters of Male Rats Induced with Valproic Acid

“…In further studies, the biochemical and molecular analyses will be performed to explain additional mechanisms of how the MC could prevent such adverse effects. The protective tissue damage effect demonstrated in this study is a phytotherapeutic property of MC extract besides other pharmacological properties shown in previous reports (Zheng et al;Jung et al, 2013aJung et al, , 2013bLiu et al;Chuethong et al;Tien et al;Kang et al;Tsoi et al;Xiao et al, 2007Xiao et al, , 2009Rajput et al, 2007Rajput et al, , 2010. Moreover, MC extract indeed did not affect any male reproductive parameters including testicular histology as compared to the control.…”

“…Recently, various scientific studies have shown that MC fruit extract has antioxidant and pharmacological properties (Kubola & Siriamornpun, 2011). MC has been demonstrated to have anti-cancer activities (Zheng et al, 2014;Jung et al, 2013a;Liu et al, 2012;Chuethong et al, 2007;Tien et al, 2005). In addition, it was also reported for its anti-inflammatory effect (Jung et al, 2013b) and angiogenesis (Kang et al, 2010).…”

Antioxidant and Hypoglycemic Effects of Momordica cochinchinensis Spreng: (Gac) Aril Extract on Reproductive Damages in Streptozotocin (STZ)-Induced Hyperglycemia Mice

“…This plant was identified to have various phytochemical components (Ishida et al, 2004;Kubola & Siriamornpun, 2011). These fruits have been reported to have antioxidant activity (Kubola & Siriamornpun), anti-inflammatory effect (Jung et al, 2013), immunomodulatory activity (Tsoi et al, 2006), antitumor properties (Chuethong et al, 2007), anti-cancer activity (Zheng et al, 2014;Petchsak & Sripanidkulchai, 2015). However, there was no report of the hypoglycemic effect of Gac aril (GA) on adverse male reproductive system in type-I DM animal model.…”

Evaluation of direct antiviral activity of the Deva-5 herb formulation and extracts of five Asian plants against influenza A virus H3N8

“…In traditional medicine, M. cochinchinensis is used to treat liver, stomach and kidney disorders, and it has detoxifying and antipyretic properties [9]. The anti-inflammatory, anti-oxidant, and antitumor activities of M. cochinchinensis have been demonstrated [11-13]. H. erectum is used to cure infectious disorders in traditional medicine, and it has antibacterial, antinociceptive and antipyretic properties [9].…”