title: Low molecular weight chitosan is an efficient inhibitor of ribonucleases.
abstract: RNase inhibitors are commonly used to block the RNase activity in manipulations with RNA-containing preparations. Recently RNase inhibitors, either synthetic or natural, have been intensively sought because they appeared to be promising for therapy of cancer and allergy. However, there is only a limited number of efficient RNase inhibitors. We have shown that a low molecular weight chitosan (M(r) approximately 6 kDa) inhibits activity of pancreatic RNase A and some bacterial RNases with inhibition constants in the range of 30-220 nM at pH 7.0 and ionic strength 0.14 M. The preferential contribution to the chitosan complex formation with RNases is due to establishment of 5-6 ion pairs. The results of this work show that polycations may efficiently inhibit ribonuclease activities.
authors: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia. yakovlev@imb.ac.ru
authors: Gennady I
authors: GI
authors: Yakovlev
authors: Vladimir A
authors: VA
authors: Mitkevich
authors: Nina K
authors: NK
authors: Struminskaya
authors: Valery P
authors: VP
authors: Varlamov
authors: Alexander A
authors: AA
authors: Makarov
mesh_terms: D002151:Calorimetry / Q000379:methods; D002384:Catalysis / Q000187:drug effects; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D007700:Kinetics; D008970:Molecular Weight; D011069:Poly I / Q000378:metabolism; D012260:Ribonucleases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D004365:Drugs, Chinese Herbal; D004791:Enzyme Inhibitors; C120250:choto-san; D011069:Poly I; D012965:Sodium Chloride; D012260:Ribonucleases