title: Purification and characterization of novel proteinase inhibitors from dried figs.
abstract: Two types of the natural organic matter P and B were isolated from dried figs by gel permeation and high-performance liquid chromatography. The characterizations of their molecular structures were also performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and infrared absorption spectrometry. As a result, these samples were revealed to inhibit the serine and cysteine proteinases chymotrypsin and papain (K(i) = 10(-)(6)-10(-)(4) M). The optimal inhibitory pH values of the P and B samples were observed to be approximately 5.5 and 5.0, respectively. The analyses of their UV-vis absorption spectra and infrared absorption spectra indicated that they would be a kind of humic substance. The mass spectrometry analyses showed that they possessed relatively small heterogeneous molecules with molecular masses around 692, 845, and 1389 Da for the P sample and around 551, 704, and 909 Da for the B sample.
authors.affiliation: Department of Biological Sciences, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan. hatano@ bce.gunma-u.ac.jp
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Hatano
mesh_terms: D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D030681:Ficus / Q000737:chemistry*; D005519:Food Preservation; D005638:Fruit / Q000737:chemistry*; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010206:Papain / Q000037:antagonists & inhibitors; D011480:Protease Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013055:Spectrophotometry, Infrared
chemical_list: D006812:Humic Substances; D011480:Protease Inhibitors; D002918:Chymotrypsin; D010206:Papain