TY - JOUR T1 - Oryzacystatin-II, a cystatin from rice (Oryza sativa L. japonica), is a dimeric protein: possible involvement of the interconversion between dimer and monomer in the regulation of the reactivity of oryzacystatin-II. AU - Ohtsubo,Sadami, AU - Taiyoji,Mayumi, AU - Kawase,Tomokazu, AU - Taniguchi,Masayuki, AU - Saitoh,Eiichi, Y1 - 2007/02/13/ PY - 2007/2/14/pubmed PY - 2007/6/21/medline PY - 2007/2/14/entrez SP - 1762 EP - 6 JF - Journal of agricultural and food chemistry JO - J Agric Food Chem VL - 55 IS - 5 N2 - We examined the biochemical and structural properties of oryzacystatin-II, a phytocystatin in rice (Oryza sativa L. japonica), under heat-stress conditions. The enzyme inhibitory reactivity of oryzacystatin-II was enhanced by heating in a temperature-dependent manner and reached a maximum level by heating at 65 degrees C for 10 min. Size-exclusion chromatography showed that oryzacystatin-II forms a homodimer at ambient temperature and that the enhancement of inhibitory reactivity is due to the conversion of the dimeric to a monomeric form. The monomeric form of oryzacystatin-II reverted to the dimer during storage at 4 degrees C, suggesting that dimerization is an intrinsic property of oryzacystatin-II. The affinity of the monomer for cysteine proteinases was significantly higher than that of the dimer. This is the first paper to describe the noncovalent dimerization for a cystatin under nonstress conditions. SN - 0021-8561 UR - https://www.unboundmedicine.com/medline/citation/17295505/Oryzacystatin_II_a_cystatin_from_rice__Oryza_sativa_L__japonica__is_a_dimeric_protein:_possible_involvement_of_the_interconversion_between_dimer_and_monomer_in_the_regulation_of_the_reactivity_of_oryzacystatin_II_ L2 - https://doi.org/10.1021/jf062637t DB - PRIME DP - Unbound Medicine ER -