Calcium ions make phytohemagglutinin resistant to trypsin proteolysis.
To investigate the mechanism of phytohemagglutinin (PHA) susceptibility or resistance to the action of proteolytic enzymes, its in vitro proteolysis by trypsin was studied. It was found that Ca (2+) gives resistance to the native PHA molecule to trypsin proteolysis. In the absence of Ca (2+) trypsin performs a thorough hydrolysis of PHA. At the first stage of trypsin hydrolysis of PHA the formation of a relatively stable high molecular mass product occurs (PHA-T) as a result of non-co-operative proteolysis. At the second stage, the degradation of PHA-T occurs, and this degradation is performed by parallel co-operative proteolysis. This type of proteolysis differs from the action of trypsin on phaseolin, the main storage protein from common bean ( Phaseolus vulgaris L.). The implications of Ca (2+)influence of PHA hydrolysis by trypsin are discussed.
Morari
Diana
D
Laboratory of Plant Biochemistry, State University of Moldova, Mateevici str. 60, MD-2009 Kishinev, Republic of Moldova.
Stepurina
Tatiana
T
Rotari
Vitalie I
VI
D002118:Calcium / Q000494:pharmacology*; D002122:Calcium Chloride / Q000494:pharmacology; D002413:Cations, Divalent; D004492:Edetic Acid / Q000494:pharmacology; D006868:Hydrolysis; D010835:Phytohemagglutinins / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism*
D002413:Cations, Divalent; D010835:Phytohemagglutinins; D010940:Plant Proteins; C048826:phaseolin protein, Phaseolus vulgaris; D004492:Edetic Acid; D014357:Trypsin; D002122:Calcium Chloride; D002118:Calcium