Synergistic Caseinolytic Activity and Differential Fibrinogenolytic Action of Multiple Proteases of Maclura spinosa (Roxb. ex Willd.) latex

BACKGROUND: Kollamalayaali tribes of South India use latex of Maclura spinosa for milk curdling. This action is implicated to proteases which exhibit strong pharmacological potential in retardation of blood flow and acceleration of wound healing. OBJECTIVE: To validate the presence of a proteolytic enzyme(s) in Maclura spinosa latex (MSL), and to investigate their probable role in hemostasis. MATERIALS AND METHODS: Processed latex was examined for proteolytic and hemostatic activity using casein and human fibrinogen as substrates, respectively. Caseinoltyic activity was compared with two standard proteases viz., trypsin I and trypsin II. Effect of various standard protease inhibitors viz., iodoacetic acid (IAA), phenylmethylsulfonyl fluoride (PMSF), ethylene glycol tetraacetic acid, and ethylenediaminetetraacetic acid on both caseinolytic and fibrinogenolytic activities were examined. Electrophoretogram of fibrinogenolytic assays were subjected to densitometric analysis. RESULTS: Proteolytic action of MSL was found to be highly efficient over trypsin I and trypsin II in dose-dependent caseinolytic activity (P < 0.05; specific activity of 1,080 units/mg protein). The Aα and Bβ bands of human fibrinogen were readily cleaved by MSL (for 1 μg crude protein and 30 min of incubation time). Furthermore, MSL cleaved γ subunit in dose- and time-dependent manner. Quantitative correlation of these results was obtained by densitometric analysis. The caseinolytic activity of MSL was inhibited by IAA, PMSF. While, only PMSF inhibited fibrinogenolytic activity. CONCLUSIONS: MSL contains proteolytic enzymes belonging to two distinct superfamilies viz., serine protease and cysteine proteases. The fibrinogenolytic activity of MSL is restricted to serine proteases only. The study extrapolates the use of M. spinosa latex from milk curdling to hemostasis. SUMMARY: Proteolytic enzymes present in latex of Maclura spinosa can be assigned to two different protease superfamilies viz., serine protease and cysteine protease as revealed by the inhibitory studies of caseinolytic activity. Among them, only serine protease can be considered as hemostatically significant as inhibition of fibrinogenolytic action of Maclura spinosa latex protease is shown only by PMSF, a serine protease-specific inhibitor. Abbreviations used: MSL: Maclura spinos Latex, IAA: Iodo Acetic Acid, EDTA: Ethylene Diamine Tetra Acetic Acid, EGTA: Ethylene glycol tetra acetic acid, PMSF: Phenyl methyl sulphonyl fluoride.