Two Different Types of Inactive Renin in Human Plasma: Molecular and Kinetic Properties

1984 ◽  
Vol 67 (4) ◽  
pp. 421-425
Author(s):  
Yoichi Imamura ◽  
Kunio Hiwada ◽  
Tatsuo Kokubu

1. We separated inactive renin in human plasma into two types, adsorbed and non-adsorbed, by chromatography on a concanavalin A-Sepharose column. About 75% of fresh plasma inactive renin was adsorbed to the column, and the rest passed through it. Non-adsorbed and adsorbed inactive renins were partially purified. 2. Non-adsorbed inactive renin had a molecular weight of 48000 and an isoelectric point of 5.44. Adsorbed inactive renin had a molecular weight of 46000 and isoelectric points of 5.56 and 5.80. 3. After activation with trypsin, both activated inactive renins were similar with respect to molecular weight (45000), thermostability, Km value (0.56 μmol/l) and pH profile. But pI values of both activated inactive renins differed. 4. These results indicate that there exist in human plasma two different types of inactive renin which differ in carbohydrate composition.

1978 ◽  
Vol 55 (1) ◽  
pp. 41-50 ◽  
Author(s):  
A. A. Shulkes ◽  
R. R. Gibson ◽  
S. L. Skinner

1. The properties of inactive and active renin in human plasma and amniotic fluid were studied chromatographically. Activation was achieved at pH 3.3 with and without added pepsin. 2. Acid activation of renin was time- and temperature-dependent but was inhibited by dilution of the sample. The dilution effect was corrected by adding pepsin. Such characteristics indicate that activation at low pH is catalysed by intrinsic enzymes. 3. Separation and/or dilution of the activating enzyme during ion-exchange chromatography concealed the eluted position of inactive renin and reduced the amount recovered. Only after full activation of the eluted renin was achieved with added pepsin was a distinct peak of inactive renin exposed. 4. At pH 7.5 inactive renin carried a lower negative charge than the active enzyme. This charge difference was lost after activation. 5. No molecular-weight differences between active, inactive renin or the International Renin Standard were detected by gel filtration. No renin of larger molecular weight was present. 6. These findings will be helpful in purification studies of human inactive renin.


1977 ◽  
Vol 167 (3) ◽  
pp. 621-628 ◽  
Author(s):  
A Bella ◽  
J S Whitehead ◽  
Y S Kim

The soluble galactosyltransferase of human plasma catalysed the transfer of galactose from UDP-galactose to high- and low-molecular-weight derivatives of N-acetylglucosamine, forming a beta-1-4 linkage. The enzyme was purified by using (NH4)2SO4 precipitation and affinity chromatography on an alpha-lactalbumin-Sepharose column. The galactosyltransferase was maximally bound to this column in the presence of N-acetylglucosamine, and the enzyme was eluted by omitting the amino sugar from the developing buffer. The molecular weight of the enzyme was estimated to be 85000 by gel filtration. The assay conditions for optimum enzymic activity was 30 degrees C and pH7.5. Mn2+ ion was found to be an absolute requirement for transferase activity. The Km for Mn2+ was 0.4 mM and that for the substrate, UDP-galactose, was 0.024 mM. The Km for the acceptors was 0.21 mM for alpha1-acid glycoprotein and 3.9 mM for N-acetylglucosamine. In the presence of alpha-lactalbumin, glucose became a good acceptor for the enzyme and had a Km value of 2.9 mM. Results of the kinetic study indicated that the free enzyme reacts with Mn2+ under conditions of thermodynamic equilibrium, and the other substrates are added sequentially.


Hypertension ◽  
1980 ◽  
Vol 2 (5) ◽  
pp. 680-685 ◽  
Author(s):  
K Morimoto ◽  
M Matsunaga ◽  
A Hara ◽  
C Kawai

1980 ◽  
Vol 59 (s6) ◽  
pp. 21s-24s ◽  
Author(s):  
Kazuo Murakami ◽  
Saori Takahashi ◽  
Shigehisa Hirose ◽  
Yukio Takii ◽  
Tadashi Inagami

1. A completely inactive renin was isolated from hog kidney extract by affinity chromatography on pepstatin-aminohexyl-Sepharose and on an Affi-Gel Blue column. 2. This inactive renin had a molecular weight of 43 000 ± 1500 as determined by gel filtration on Ultrogel AcA 44. Upon activation with trypsin, its molecular weight fell to 41 000 ± 1400. 3. The inactive renin lacked the ability to bind renin-binding substance whereas trypsin-activated renin was able to bind the renin-binding protein and to form high-molecular-weight renin. 4. Chymotrypsin as well as trypsin could activate the inactive renin although less effectively. 5. The active renins generated from the inactive renin by the action of different proteolytic enzymes differed in their net charge, reflecting the specificities of the proteases used; the isoelectric points of the native, the trypsin-activated and the chymotrypsin-activated forms of renin occurred at pH 5.3, 5.1 and 4.8 respectively.


1980 ◽  
Vol 59 (s6) ◽  
pp. 29s-33s ◽  
Author(s):  
S. A. Atlas ◽  
J. H. Laragh ◽  
Jean E. Sealey ◽  
T. E. Hesson

1. Plasma prorenin (inactive renin), which accounts for about 70% of the total renin in human plasma, was almost completely separated from active renin by affinity chromatography on Cibacron blue F3G-A-agarose. The slight residual renin activity present in the prorenin peak can be removed on concanavalin A-Sepharose, demonstrating that prorenin is completely inactive. 2. The renin activity of both human renal cortical extract and renal perfusate increased after incubation with trypsin. This trypsin-activable renin accounted for 15 and 40% of the total renin in extract and perfusate respectively. 3. Trypsin-activable renin from both renal extract and renal perfusate was, like plasma prorenin, almost completely separated from active renin on Cibacron blue F3G-A-agarose. After additional chromatographic steps, the trypsin-activable renin from renal cortical extract was found to be completely inactive. 4. We conclude that human kidney contains, and is able to release, a trypsin-activable renin that resembles plasma prorenin. It may differ from many of the 60 000 molecular-weight forms of renin previously identified in renal extracts, since these possess considerable intrinsic renin activity and probably represent a complex of renin with a binding protein.


1980 ◽  
Vol 59 (s6) ◽  
pp. 37s-40s ◽  
Author(s):  
Haruyuki Nakane ◽  
Yoko Nakane ◽  
Jiro Misumi ◽  
Takao Saruta ◽  
Pierre Corvol ◽  
...  

1. Physicochemical properties of renin secreted by isolated perfused rat kidney were examined and the results compared with those obtained for the renin in renal extract. 2. In renal extract, two high-molecular-weight reruns (molecular weight 65 000 and 55 000) and one low-molecular-weight renin (molecular weight 39 000) were found. Their relative proportion varied depending on extraction conditions. By acidification, high-molecular-weight renins were converted into low-molecular-weight renin without marked changes in activity. 3. In renal perfusate only low-molecular-weight renin was found after renin stimulation by isoprenaline or anoxia. Inactive renin was not found. 4. Renin in renal extract and perfusate samples were both found to consist of at least four isoenzymes having different isoelectric points (pI). The pI patterns were identical in renal extract and perfusate samples: pI 5.7 (60-70%), 5.5 (15-25%), 5.3 (5-10%) and 5.0-5.2 (2-5%). 5. These results indicate that the native renin secreted by rat kidney consists entirely of the low-molecular-weight and active form comprising multiple isoenzymes with a stable pI pattern.


1992 ◽  
Vol 67 (04) ◽  
pp. 440-444 ◽  
Author(s):  
Hiroko Tsuda ◽  
Toshiyuki Miyata ◽  
Sadaaki Iwanaga ◽  
Tetsuro Yamamoto

SummaryThe analysis of normal human plasma by fibrin autography revealed four species of plasminogen activator (PA) activity related to tissue-type PA, factor XII, prekallikrein and urokinase-type PA (u-PA). The u-PA activity increased significantly by incubating plasma with dextran sulfate. This increase was coincident with both the cleavage of factor XII and the complex formation of activated factor XII with its plasma inhibitors, which were determined by immunoblotting procedure. The dextran sulfate-dependent activation of u-PA required both factor XII and prekallikrein, but did not require either plasminogen or factor XI. High molecular weight kininogen was required only at a low concentration of dextran sulfate. Thus the results indicate that the factor XII and prekallikrein-mediated activation of single chain u-PA (scu-PA) operates as a major pathway of scu-PA activation in whole plasma in contact with dextran sulfate.


Sign in / Sign up

Export Citation Format

Share Document