Martin Morrison

Lactoperoxidase: V. Identification and isolation of lactoperoxidase from salivary gland

Abstract Bovine tissues were analyzed for the presence of lactoperoxidase by immunodiffusion analysis. A protein antigenically identical to lactoperoxidase was shown to be present in the sublingual, submaxillary, and parotid glands. An antigenically related but not identical protein was present in pig salivary glands. As the enzyme could not be detected in any of the other tissues employed, it could be concluded that if present, it represented less than 0.04% of the extracted protein. Most notable among the tissues which did not contain the enzyme, are the thyroid, uterus, and lymph node. A method is presented for the isolation of lactoperoxidase from the submaxillary gland. The enzyme is a major protein of this tissue, comprising between 1 and 2% of the wet weight of the tissue. The relationship of lactoperoxidase to peroxidase activity reported in other studies of the salivary gland is discussed. It is clear that the “salivary peroxidase” and “iodide peroxidase” can be attributed to lactoperoxidase.

Hexose-6-Phosphate Dehydrogenase Found in Human Liver

Starch-gel electrophoresis of extracts of human liver revealed the presence of a new hexose-6-phosphate dehydrogenase that was slower-moving at pH 8.6 than the sex-linked glucose-6-phosphate dehydrogenase. When the gel plate was stained, galactose-6-phos phate being used as a substrate, this enzyme band stained intensely, but the sex-linked glucose-6-phosphate dehydro genase failed to stain. This new human enzyme may well be homologous with the autosomally inherited glucose-6-phosphate dehydrogenase of the deer mouse (Peromyscus maniculatus), re ported by Shaw and Barto.

Determination of heme a concentration in cytochrome preparations by hemochromogen method

Abstract A method for the determination of the heme a concentration in cytochrome c oxidase and cytochrome a preparations has been evaluated. Heme a in similar preparations will form a number of derivatives with functional groups of the protein. These reactions and their effect on the results of hemochromogen determinations are presented. The m M extinction coefficient of purified cytochrome c oxidase in the reduced form at 603 mμ is 21.6 and at 443 mμ is 108, while the m M extinction coefficient of cytochrome a at 601 mμ is 22.8 and at 439 mμ is 94.1.

Lactoperoxidase: Identification and Isolation from Harderian and Lacrimal Glands

Investigation of bovine lacrimal and harderian glands revealed the presence of the enzyme lactoperoxidase, which was isolated and purified. A nonheme, iron-containing protein was identified at the same time. Both proteins are present in milk, mammary glands, and salivary glands. Their roles are discussed: The lactoperoxidase may be important in controlling bacterial flora.

Genetic Control of Lactate Dehydrogenase Formation in the Hagfish Eptatretus stoutii

The isozyme patterns of lactate dehydrogenases of various tissues were studied on 51 hagfish by starch-gel electrophoresis. Nine lactate dehydrogenase phenotypes were encountered, suggesting the coexistence of two alleles at each of the two separate gene loci. There apparently was no interaction between the products of these two separate loci. Even the products of two alleles at the same locus were apparently incapable of forming hybrid molecules, an indication of the possible monomeric nature of each lactate dehydrogenase molecule.

Multiple gene loci for the monomeric hemoglobin of the hagfish (Eptatretus stoutii).

The fact that members of the subclass Cyclotomata possess monomeric hemoglobin molecules has been known for some time. Electrophoresis of hemolysates from 12 hagfish (Eptatretus stoutii) revealed five hemoglobin phenotypes with four to six distinct zones of hemoglobin. Each zone is believed to represent a monomer containing one heme group on a single polypeptide chain with a molecular weight of approximately 18,000. It is postulated that these monomers are controlled by genes at four loci.

Lactoperoxidase. IV. Immunological analysis of bovine lactoperoxidase preparations obtained by a simplified fractionation procedure

Abstract Antiserum to crude lactoperoxidase was employed in agar diffusion and immunoelectrophoretic analyses of fractions obtained in the isolation and purification of lactoperoxidase from cows milk by ion-exchange chromatography and gel filtration. The presence of seven antigenic components could be detected in a crude enzyme preparation by immunological analysis and their fate monitored during the purification procedure. Purified lactoperoxidase, prepared by ion-exchange chromatography and gel filtration, was found by immunological analysis to consist of a single antigenic component.

Cytochrome c oxidase: VIII. Lipid content☆

Abstract A study of the lipids contained in purified preparations of cytochrome c oxidase has been made. Other than the cholate which had been added as a solubilizing agent, only about 0.05 mg of lipid per milligram of protein was present. The phospholipid content did not exceed 9 μg per milligram protein in any preparation analyzed. For the most part, the lipids could be identified with the degradation products of naturally occurring lipid. These results suggest that in the isolated cytochrome c oxidase system, although solubilizing agents are required to achieve high enzyme activity, there is little or no specificity required for phospholipid.

Distinction of cytochromes a and a3 by chemical reactivity

Abstract Almost a quarter of a century after Keilin and Hartree (1939) first distinguished cytochrome a 3 from cytochrome a, there is still no uniform agreement that these two cytochromes are distinct. The evidence for two distinct cytochromes is based on the spectral properties of the cytochromes and on reactions with carbon monoxide and cyanide ( Chance, 1953 ; Horie and Morrison, 1962; Lundegardh, 1957; Smith, 1955; Yonetoni, 1961 ). The validity of this evidence has been questioned ( Okunuki, 1962; Wainio, 1961 ). It has been suggested that purified preparations give no evidence for two cytochromes, and that the spectra with carbon monoxide or cyanide does not establish two cytochrome components ( Okunuki, 1962; Wainio, 1961 ). Further, physical and chemical methods have failed to separate “cytochrome a” into two cytochrome components. It is the object of this communication to present, in preliminary form, evidence that the carbon monoxide combining cytochrome component, cytochrome a 3 , is chemically distinguishable from cytochrome a.

THE CYTOCHROME C OXIDASE COMPONENTS. VI. EFFECT OF BOROHYDRIDE ON PRESUMED "OXYGENATED COMPLEX".

Abstract A study of the effect of borohydride on the so-called “oxygen complex” of Okunuki has been made. The evidence that borohydride will not reduce oxidized cytochrome c oxidase but will reduce “the oxygenated complex” is questioned. It is suggested that borohydride can reduce cytochrome c oxidase because of its ability to reduce oxidation products of dithionite.