Studies on the elastolytic activity of serum

Determination of Elastolytic Activity with 125I and 131I Labelled Elastin

“…It is very sensitive, can be used in colored or turbid media in a great variety of conditions. As the "label" is covalently fixed on the elastic fiber it does not "elute" with certain protein solutions [ 5 ] .…”

“…Crystalline trypsin had a very low, hardly detectable activity and plasmin had no activity Several different methods were described for the determination of elastolytic activity (for a review see Mandl [l] and Banga [S]). Most of these methods suffer from one of the following drawbacks: lack of sensitivity (the gravimetric and turbidimetric methods) [3,4] elution of the non-covalently bound dye by proteins as demonstrated by Banga [5] ; modification of the charge profile of the elastin fibers by the introduction of dye molecules [6,7] or interference with the reading at a critical wave-length if the enzyme is not sufficiently purified as in body fluids, cell or tissue suspensions. I n order to overcome these difficulties, we propose a new method based on the use of 1311 and lZ5I labelled elastin.…”

“…Crystalline trypsin had a very low, hardly detectable activity and plasmin had no activity Several different methods were described for the determination of elastolytic activity (for a review see Mandl [l] and Banga [S]). Most of these methods suffer from one of the following drawbacks: lack of sensitivity (the gravimetric and turbidimetric methods) [3,4] elution of the non-covalently bound dye by proteins as demonstrated by Banga [5]…”

Isolation of Elastase from Human Serum

“…The nature of the leucocyte actin polymer formed in the presence of Mg2+ ions is not yet known, but this may be a general property of cytoplasmic actins. Plasmodium actin has been shown to form a similar 'magnesium-polymer'(HatanoetaI., 1967; Hatano, 1972) with propertiesdifferent from F-actin in that it is more flexible and continues to hydrolyse ATP after assembly.It has been suggested (Hall, 1971) that the production of the enzyme-substrate complex in elastolysis is accomplished by the formation of a co-ordinate linkage between elastase and elastin through a calcium atom. Elastase can exist in two forms (Hall et a/., 1973).…”

“…The nature of the leucocyte actin polymer formed in the presence of Mg2+ ions is not yet known, but this may be a general property of cytoplasmic actins. Plasmodium actin has been shown to form a similar 'magnesium-polymer'(HatanoetaI., 1967; Hatano, 1972) with propertiesdifferent from F-actin in that it is more flexible and continues to hydrolyse ATP after assembly.…”