Peptide elongation factor 1 from yeasts: purification and biochemical characterization of peptide elongation factors 1 alpha and 1 beta (gamma) from Saccharomyces carlsbergensis and Schizosaccharomyces pombe

Cytoplasmic elongation factor 1 alpha (EF-1 alpha) [corrected] was purified to homogeneity in high yield from the two different yeasts Saccharomyces carlsbergensis (S. carls.) and Schizosaccharomyces pombe (S. pombe). The purification was easily achieved by CM-Sephadex column chromatography of the breakthrough fractions from DEAE-Sephadex chromatography of cell-free extracts. The basic proteins have a molecular weight of 47,000 for the S. carls. factor and of 49,000 for the S. pombe factor. While the purified yeast EF-1 alpha s function analogously to other eukaryotic factors and the E. coli EF-Tu in Phe-tRNA binding and polyphenylalanine synthesis, the yeast factor unusually hydrolyzed GTP on yeast ribosomes upon addition of Phe-tRNA in the absence of poly(U) as mRNA. This novelty is probably owing to the yeast ribosomes, which are assumed to lack elongation factor 3-equivalent component(s). Trypsin and chymotrypsin selectively cleaved the two yeast factors to generate resistant fragments with the same molecular weight of 43,000 (by trypsin) and of 44,000 (by chymotrypsin), respectively. Those cleavage sites were characteristically protected by the presence of several ligands bound to EF-1 alpha such as GDP, GTP, and aminoacyl-tRNA. Based on the sequence analysis of the fragments generated by the two proteases, the partial amino acid sequence of the S. carls. EF-1 alpha was deduced to be in accordance with the N-terminal region covering positions (1) to 94 and two Lys residues at the C-terminal end of the predicted total sequence of the Saccharomyces cerevisiae (S. cerev.) factor derived from DNA analysis, except for a few N-terminal residues, confirming the predicted S. cerev. sequence at the protein level. EF-1 beta and EF-1 beta gamma were isolated and highly purified as biologically active entities from the two yeasts. EF-1 beta s from the two yeasts have the same molecular weight of 27,000, whereas component gamma of the S. carls. EF-1 beta gamma showed a higher molecular weight (47,000) than that of the S. pombe factor (40,000). It was also shown that a stoichiometric complex was formed between EF-1 alpha and EF-1 beta gamma from S. pombe. Furthermore, a considerable amount of Phe-tRNA binding activity was distributed in the EF-1H (probably EF-1 alpha beta gamma) fraction from freshly prepared cell-free extracts of yeast.

Activation mechanism of monkey and porcine pepsinogens A. One-step and stepwise activation pathways and their relation to intramolecular and intermolecular reactions

The activation of Sepharose-bound monkey pepsinogen A under acidic conditions proceeded by cleavage of the Leu47-Ile48 bond, indicating the occurrence of the intramolecular one-step activation, although the rate of cleavage was very slow. On the other hand the activation of monkey pepsinogen A in solution was highly dependent on pepsinogen concentration and the addition of exogenous pepsin A accelerated the rate of activation, indicating the predominance of intermolecular reaction. The cleavage site, however, was also restricted to the Leu47-Ile48 bond. Thus, apparently exclusive one-step activation occurred in monkey pepsinogen. The activation of porcine pepsinogen A in solution was also dependent on pepsinogen concentration and the addition of exogenous pepsin A accelerated the rate of activation. The major cleavage site by the exogenously added pepsin was the Leu44-Ile45 bond. Therefore the site most susceptible to the intermolecular attacks was the bond connecting the activation segment and the pepsin moiety in both monkey and porcine pepsinogens. In porcine pepsinogen, however, a part of the zymogen was activated through the intermediate form, and an intramolecular reaction was suggested to be involved in the generation of this form. These results showed that in both pepsinogens A the intramolecular reaction occurred, first yielding pepsin A or the intermediate form, which then acted intermolecularly on the remaining pepsinogen or the intermediate form to complete the activation in a short time. A molecular mechanism for the activation reaction was proposed to explain consistently the experimental results.

[A public health view of seamen's wives. Role of the mother during the father's absence]

The health status of 59 wives of seamen during their absence from home being on board a ship was evaluated by THI (Tokyo University Health Inventory). There was no evidence that the absence of their husbands had any undesirable effects on their health, but those who received fewer telephone calls from their absent husbands complained more frequently of subjective symptoms related to mental problems. The same tendency was observed in those who sought advice from their neighbors and others at times of trouble with their children. A qualitative analysis of communication between the wives of seamen and their husbands or other social network and evaluation of the mother-infant relationship should be conducted in the future.

[Clinical investigation of serum immunosuppressive acidic protein (IAP) in patients with gastric cancer]

Immunosuppressive acidic protein (IAP) is among the immunosuppressive factors so far detected in the blood of cancer patients. This study was undertaken to determine the blood level of IAP in patients with carcinoma of the gastrointestinal tract, particularly the stomach, and to define the clinical implications of IAP for the therapy. A close correlationship was established between the serum IAP level and the gross degree of malignancy of the tumor and clinical stage of disease, notably in patients with gastric cancer; the serum IAP level was increased with as the disease advanced, the increase being significant in the presence of metastasis or extensive spread of the lesion.

Isolation and characterization of bovine and mouse terminal deoxynucleotidyltransferase cDNAs expressible in mammalian cells

We have isolated nearly full-length cDNA clones of terminal deoxynucleotidyltransferase (TdT) from calf thymus and mouse lymphoma cDNA libraries. The libraries were constructed using the pcD vector system which permits the expression of cDNA inserts in mammalian cells. The bovine TdT cDNA clone contains an open reading frame coding for 520 amino acids, Mr 59,678. The mouse TdT cDNA clone contains an open reading frame of 1,587 bp, whose translated cDNA encodes a 60,004 dalton protein. The mouse TdT cDNA clone contains 60 bp in the 3' end region of the coding sequence not found in the bovine TdT cDNA sequence, otherwise, the clones share about 80% homology. A possible nuclear-localization-sequence (Pro-Arg-Lys-Lys-Arg-Pro-Arg) was conserved in the N-terminal region in the mouse and bovine cDNA clones. Bovine and mouse cDNAs transfected into COS7 monkey fibroblasts directed the synthesis of enzymatically active protein of Mr 60,000 which was detected immunologically using polyclonal rabbit antibody against bovine TdT. Bovine TdT expressed in COS7 cells by nearly full-length cDNA clone was localized in the nucleus and the translational product of pOK103 lacking the nuclear-localization-sequence was localized in the cytoplasm.

The complete amino acid sequence of monkey pepsinogen A

The complete amino acid sequence of pepsinogen A from the Japanese monkey (Macaca fuscata) was determined. After converting the pepsinogen to pepsin by activation, the pepsin moiety was reduced and carboxymethylated, cleaved by cyanogen bromide, and the amino acid sequences of the major fragments determined. These fragments were aligned with the aid of overlapping peptides isolated from a chymotryptic digest of intact pepsin. Since the sequence of the activation segment had been determined previously (Kageyama, T., and Takahashi, K. (1980) J. Biochem. (Tokyo) 88, 9-16), the 373-residue sequence of monkey pepsinogen A was established, consisting of the pepsin moiety of 326 residues and the activation segment of 47 residues. Three disulfide bridges and 1 phosphoserine residue were found to be present in the pepsinogen molecule. The molecular weight was calculated to be 40,027 including the phosphate group. Monkey pepsinogen A showed high homology with human (94% identity) and porcine (86% identity) pepsinogens A.

The complete amino acid sequence of monkey progastricsin

The complete amino acid sequence of progastricsin from the Japanese monkey (Macaca fuscata) was determined. Progastricsin is composed of 374 residues, including the gastricsin moiety of 331 residues and the activation segment of 43 residues. Upon activation under acidic conditions, progastricsin was converted to gastricsin via the intermediate protein species. NH2-terminal sequence determination of these protein species enabled us to deduce the NH2-terminal 78-residue sequence of progastricsin, including the 43-residue activation segment. The complete sequence of the gastricsin moiety was determined using peptide fragments obtained by several chemical and enzymatic cleavages. The molecular weight of progastricsin was determined to be 40,785. As compared with pepsinogen A of the same monkey species, deletion of 4 residues and insertion of 5 residues were observed. Although monkey progastricsin and pepsinogen A have highly homologous sequences around the two active site aspartyl residues, the homology between these proteins is rather small (49% identity). This indicates that progastricsin diverged from pepsinogen A in the early phase of the evolution of gastric aspartyl proteinases.

Purification of Japanese monkey prostate acid protease zymogen and its identification as a pepsinogen C-like zymogen

A pepsinogen C-like acid protease zymogen was found in Japanese monkey prostate extract and seminal plasma by means of the double immunodiffusion method using rabbit anti-pepsinogen C antiserum, and was purified from the prostate by a combination of ammonium sulfate fractionation, DEAE-Sephacel chromatography, Sephadex G-100 gel filtration, and immunoadsorption to an anti-pepsinogen C column. The zymogen was purified 6,400-fold in a yield of 13.1%. The purified zymogen gave a single band on polyacrylamide gel electrophoresis both in the presence and absence of sodium dodecyl sulfate. The zymogen was converted to the active form by acid treatment at pH 2.8 for 4 h with concurrent reduction of the molecular weight from 41,000 to 36,000. By the double immunodiffusion method, prostate pepsinogen C-like acid protease zymogen, pepsinogen C, lung procathepsin D-II, and their active forms gave a single, fused precipitin line in agar plate with anti-pepsinogen C antiserum, which did not react with cathepsin D and pepsinogen A. Furthermore, the optimal pH of 2.5-3.0, the effect of pepstatin on the activity, and the amino acid compositions were also in good agreement among these three zymogens, showing that they are very similar protease zymogens.

Monkey pepsinogens and pepsins. VII. Analysis of the activation process and determination of the NH2-terminal 60-residue sequence of Japanese monkey progastricsin, and molecular evolution of pepsinogens

Japanese monkey progastricsin was shown to be activated to gastricsin exclusively by a two-step process through an intermediate form. The occurrence of this process was substantiated by the isolation of the intermediate form and released peptides. By NH2-terminal sequence analyses of these protein and peptide species, the amino acid sequence of the 43-residue activation segment (propart) was determined to be as follows: (Formula: see text) The NH2-terminal 26-residue peptide was released first, resulting in generation of the intermediate form. The subsequent release of peptides, residues Nos. 27-40 and 27-43, generated two gastricsins as the final products. This two-step process of activation of Japanese monkey progastricsin is in striking contrast to the one-step activation process occurring exclusively for pepsinogen A of the same monkey species. The course of molecular evolution of pepsinogens including progastricsins was deduced from the amino acid sequences of their activation segments by constructing phylogenic trees. The trees divided pepsinogens into 3 clusters, i.e., pepsinogens A, progastricsins and prochymosin, showing that these three groups diverged from one another very early on in the course of the evolution of pepsinogens.

A multicenter double-blind controlled study of lobenzarit, a novel immunomodulator, in rheumatoid arthritis

A multicenter double-blind study was carried out in patients with rheumatoid arthritis (RA) by comparing treatment with a novel immunomodulator, lobenzarit, disodium 4-chloro-2, 2'-iminodibenzoate, with an inert placebo. Both groups of patients received 75 mg/day of indomethacin as a basal regimen during the study period of 16 weeks. Group 1 (115 patients) received 240 mg/day lobenzarit, 80 mg TID, and Group 2 (115 patients) received placebo TID orally. A statistically significant improvement was noted in the number of swollen joints and in the Lansbury index at Weeks 12 and 16 in Group 1 as compared to Group 2. Overall clinical effectiveness was significantly higher in Group 1 (63%) than in Group 2 (43%). Incidence of side effects was 38% in Group 1 and 22% in Group 2. The most frequent side effect in both groups was gastrointestinal upset. Our data confirm that lobenzarit is a useful agent in the treatment of patients with RA.

Rabbit pepsinogens. Purification, characterization, analysis of the conversion process to pepsin and determination of the NH2-terminal amino-acid sequences

Six pepsinogens were purified from the gastric mucosa of adult rabbits by chromatographies on DEAE-cellulose, DEAE-Sephacel and Sephadex G-150. They were designed as pepsinogen I, pepsinogens II-1, II-2, II-3, and II-4, and pepsinogen III, based on their chromatographic behaviors. Each pepsinogen was converted to pepsin at pH 2.0 and 14 degrees C. The resulting pepsins had roughly similar enzymatic properties. However, activation processes appeared to differ significantly among them. Pepsinogen I was converted to an active intermediate form by sequentially releasing the NH2-terminal 25 or 26 residues. This active form was fairly stable and no further conversion occurred on further incubation for several hours. Pepsinogens II were converted to pepsins partly sequentially through intermediate forms and partly directly releasing the NH2-terminal 44 residues as a single intact polypeptide. Pepsinogen III appeared to be converted to pepsin directly without forming intermediate species. The amino acid sequences of the activation segments of these pepsinogens were determined together with the sequences in the NH2-terminal regions of the resulting pepsins. Five distinct sequences were identified, indicating that most of these pepsinogens are the products of different genes.