Globulin definition

A definitive identification of the proteins in each peak is not possible, however, the elution times of the peaks at 13-14 min. and 15 min. are close to the times which would be expected for gamma-globulins and albumins, two of the principal classes of serum proteins. These data also indicate the loading capacity of this column with serum. More than 14 mg. of undiluted serum was injected before evidence of overloading in the form of band broadening and peak distortion was observed. 

Globulin A classic definition of proteins that are insoluble in water and soluble in... 

No definitive study of the effects of protein carrier on response is available, and many carrier proteins have been used, including globulins, albumin, hemocyanin, thyroglobulin, and fibrinogen. The optimal number of haptens, or the epitope density, is also controversial, but a density of 8 to 25 haptens per bovine serum albumin molecule is probably optimal (12),... 

Pedantry introduced the term hypogammaglobulinemia (although we are all quite happy to talk about anemia). Deficiency of IgG can be arbitrarily defined as severe when the serum level is less than 200 mg/100 ml 20% MNA, see Section 6.2 and Table 4), or moderate when from 200 to the —2 SD lower limit of normal for age, and in this review I use the terms severe AG and moderate AG to describe these. During the first 6 months of life, infants commonly show levels below 20% MNA, so that in this period 10% MNA (100 mg/100 ml) is better used as the arbitrary limit (Mil). Although these definitions are arbitrary they are useful in that it is known that within one year 70% of patients with severe AG will suffer severe infection (H19) and that without treatment 65% may die (MU). Moderate AG is complicated within a year by severe infection 40% (H19), but as this is so common (H25, MU) my present policy is chiefly to observe such patients some will earn their y-globulin treatment, others can manage with supportive measures such as early treatment of any infection. 

Regarding the more definitive weapon of the complement cascade, it has recently been demonstrated that the administration of supplemental sodium ascorbate to guinea pigs significantly increases the esteratic power of the first component of complement (C, esterase activity, without which the whole complement cascade is inoperable) in animals immunized with antipenicilloyl (guinea pig)-y-globulin. ... 

Not all proteins adsorbed in silica are denatured. At least gamma globulins that. are adsorbed on powdered quartz retain their antigenic specificity. Pernis, Clerici, and Ghezzi (273) concluded that this shows that the immunological reactions of silicosis could not be due to antibody production against serum proteins altered, by quartz. However, other types of proteins are definitely denatured and may be the cause of the reactions. . ... 

In the blood plasma of mammals there is present a -pseudo-globulin called transferrin or siderophilin, and which at a definite point in its molecule forms an iron complex. This protein, whose molecular weight is in the region of 90,000, makes up about 3% by weight of the plasma proteins. The iron is complexed by it in the ferric form and only in the presence of COg. When the level of iron in the plasma is at its normal value, which in man is 129y/100 ml., the transferrin is saturated to the extent of 30% of the maximum amount of iron which it can carry. The same protein can also fix copper. 

Fractionation of proteins is too large a field to be completely reinewed here, but certain facts stand out clearly. The distinction between different classes of proteins, e.g., albumins and globulins, was for a long time made completely on the basis of solubility in water, salt solutions and other solvents. The inadequacy of such a method of classification was pointed out by Block, who attempted to introduce chemical factors into it as well. Butler and coworkers (204) had previously shown that albumin and globulin separation by neutral salts was not sharp, and that there was much overlapping of the fractions. Duli e (205) found i>oor agreement between the sodium sulfate method of Howe (206) and the ammonium sulfate method, while Macheboeuf (207) concluded from a comparative study of several fractionation methods, that the definitions of the protein fractions were indefinite unless the method of separation was specified. 

In considering plasma as protein food its metabolism when injected intravenously must necessarily be compared with the behavior of the same protein when taken by mouth, inasmuch as there is such a difference in the mechanisms involved. Study of the nutritional value of plasma protein when given by mouth has resulted in a variety of results. For example, it has been shown (52) that following oral administration positive balance can be achieved in dop with precipitated washed bovine serum at a level comparable to that of casein. This same worker (53) as well as others (77, 80) has shown that beef serum by mouth is of high nutritional value in respect to plasma protein regeneration in protein depleted dop. On the other hand, powth experiments with human plasma have definitely shown nutritional deficiencies (10, 37) which are confined to the albumin fraction. By contrast, globulin and fibrin are of high nutritive value. The deficiency in albumin apparently is due to a lack of isoleucine and tryptophan this was shown not only... 

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