Full resolution (JPEG) - On this page / på denna sida - V. The Blood - I. Blood-plasma and Blood-serum - The Blood-plasma
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
SEKGLOBULINS. 259
cannot be completely and positively separated from each other. The
mixture of globulins obtained from blood-plasma or blood-serum hy
saturation with magnesium sulphate or half-saturation with ammonium
sulphate consists of nucleoprotein, fibrin-globulin, and the true serglobulin
or mixture of globulins.
The nucleoprotein has been previously discussed. The fibrin-globulin,
which occurs in the serum only in small amounts, can be completely pre-
cipitated by NaCl. It has the general properties of the globulins, but
differs from the serglobulins by a lower coagulation temperature, 64-
66° C, and also in that it is precipitated by (NH^SCU even in 28 per
cent solution.
Serglobulins. If the globulin obtained by saturation with magnesium
sulphate is dialyzed, then, as has been known for a long time and further
substantiated by Marcus, only a part of the globulin separates out,
while a portion remains in solution and cannot be precipitated by the
addition of acid. For this reason Marcus 1
also differentiates between
a water-soluble globulin and one insoluble in water. According to the
later investigations of Hofmeister and Pick 2
the part insoluble in
water corresponds chiefly to a globulin fraction readily precipitated by
(NH4)2S04 (by 28-36 vols, per cent saturated solution), and the part
soluble in water corresponds to a fraction difficult to precipitate (by
36-44 vols, per cent saturated solution). The first fraction is called
euglobulin and the second pseudoglobulin. According to Porges and
Spiro 3
the serglobulins can be separated by (NHU^SO-t into three
fractions whose precipitation limits are 28-36, 33-42, and 40-46 vols,
per cent saturated solution. All three fractions contain globulin insoluble
in water. Freund and Joachim 4
have found that the euglobulin as
well as the pseudoglobulin fraction is a mixture of globulin soluble in
water and globulin insoluble in water, and consequently the number
of different globulins in the serum may be still greater.
It follows from all these investigations that either the difference between
the globulin soluble in water and that insoluble is not sufficient or that the frac-
tional precipitation with ammonium sulphate is not suited for the separation
of the various globulins. This latter seems to be the case, as shown by Mellanby
Haslam and recently by Wiener. 5
It must not be forgotten that the globulin
fractions are always contaminated with other serum constituents, and that these
may influence the solubility and precipitability. As Hammarsten has shown,
a water-soluble globulin, can be transformed into a globulin insoluble in water
1
Zeitschr. f. physiol. Chem., 28.
2
Hofmeister’s Beit rage, 1.
Hofmeister’s Beit rage, 3.
4
Zeitschr. f. physiol. Chem., 36.
5
Mellanby, Journ. of Physiol., 36; Haslam, ibid., 32; Wiener, Zeitschr. f. physiol
Chem., 74.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
