Primary structure of murine major histocompatibility alloantigens: amino acid sequence of the cyanogen bromide fragment Ia (positions 139-228) from the H-2Kb molecule

The complete amino acid sequence of the cyanogen bromide (CNBr) fragment Ia (CN-Ia) from the murine histocompatibility antigen H-2Kb has been obtained by using radiosequence methodology. This glycopeptide is the largest CNBr cleavage product of the H-2K molecule and extends from position 139 to position 228. The sequence determined for CN-Ia was Ala-Ala-Leu-Ile-Thr-Lys-His-Lys-Trp-Glu-Gln-Ala-Gly-Glu-Ala-Glu-Arg-Leu-Arg-Ala -Tyr-Leu-Glu-Gly-Thr-Cys-Val-Glu-Trp-Leu-Arg-Arg-Tyr-Leu-Lys-Ans-Gly-(Asn)-Ala- Thr-Leu-Leu-Arg-Thr-Asp-Ser-Pro-Lys-Ala-His-Val-Thr-His-His-Ser-Arg-Pro-Asp-Asp -Lys-Val-Thr-Leu-Arg-Cys-Trp-Ala-Leu-Gly-Phe-Tyr-Pro-Ala-Asp-Ile-Thr-Leu-Thr-Tr p-Gln-Leu-Asn-Gly-Glu-Glu-Leu-Ile-Gln-Aps-Met. The data were obtained by analysis of fragments derived by thrombic, tryptic, chymotryptic, and V8 protease digestion of CN-Ia. A carbohydrate moiety is attached to Asn at position 176. Homology between this 90 amino acid stretch of H-2Kb and HLA-B7 [Orr, H. T., Lopez de Castro, J. A., Lancer, D., & Strominger, J. L. (1979) Biochemistry 18, 5711] is 68%, and differences are noted at positions 176, 177, and 178 which in the H-2 molecule are the attachment region for a second carbohydrate moiety. No carbohydrate was detected in this position for HLA-B7 [Orr, H. T. Lopez de Castro, J. A. Lancet, D., & Strominger, J. L. (1979) Biochemistry 18, 5711].

Primary structure of murine major histocompatibility complex alloantigens: completion of the sequence of the amino-terminal 284 residues of H-2Kb

The primary structure of the COOH-terminal cyanogen bromide (CNBr) cleavage fragment Ic (CN-Ic) of the extracellular portion of the murine histocompatibility antigen H-2Kb has been completed. CN-Ic contains a site of papain cleavage which has been utilized for solubilizing H-2Kb by cleaving off the membrane integrating portion of the molecule. The amino acid sequence of CN-Ic has been determined by using peptides recovered after trypsin digestion of CN-Ic before and after blockage of lysine groups with citraconic anhydride. Overlapping sequences for the tryptic fragments were obtained by amino-terminal sequence analysis. The sequence of fragment CN-Ic, which spans residues 229-284 in H-2Kb, is as follows: Glu-Leu-Val-Glu-Thr-Arg-Pro-Ala-Gly-Asp-Gly-Thr-Phe-Gln-Lys-Trp-Ala-Ser-Val-Val-Pro-Leu-Gly-Lys-Glu-Gln-Tyr-Tyr-Thr-Cys-His-Val-Tyr-Gln-Gln-Gly-Leu-Pro-Gln-Pro-Leu-Thr-Leu-Arg-Trp-Asp-Glu-Pro-Pro-Ser-Thr-Val-Ser-Asn-Met. This amino acid sequence determination completes the primary structure of the amino terminal 284 residues of H-2Kb, that portion of this histocompatibility antigen which is external to the cell membrane and which contains antigenic determinants. It was also possible to identify Val-281 as a papain cleavage site within CN-Ic. The completed structure was analyzed solely by radiochemical methods. The structure obtained for H-2Kb is 71% homologous to the reported structure of HLA-B7, a human homologue.

Biochemical studies on the H-2K antigens of the MHC mutants bm3 and bm11

Biochemical analyses of the H-2K-gene products of the C57BL/6 mutant strains, bm3 and bm11, have been carried out in order to characterize the structural relationships among these antigens. From comparative tryptic peptide mapping of cyanogen bromide fragments from the mutant and parent Kb glycoproteins and from preliminary amino-acid sequence analyses, a number of discrete differences have been discerned. Two sites of difference at amino residues 77 and 89 in the Kbm3 glycoprotein are noted relative to Kb. An alteration at residue 77 similar or identical to that seen in Kbm3 is present in the K antigen of the bm11 mutant. Because our techniques sample only 75 to 80 percent of the extracellular portion of H-2Kb, other undetected changes are possible. However, our present findings are most consistent with the conclusion that only very limited differences exist between mutant and parent molecules. Further, taken together with CML (cell-mediated-lymphocytotoxicity) reaction patterns (Melief et al. 1980), the biochemical data support the hypothesis that the proposed structural alterations in the Kb mutant glycoproteins are directly related to their observed immunological specificity.

Clinical study of niceritrol on serum lipids in the treatment of hyperlipidemia

The effects of niceritrol, a nicotinic acid derivative, on the levels of HDL-cholesterol (HDL-Ch) and a mixture of VLDL- and LDL-Ch (VLDL- + LDL-Ch) were studied in hyperlipidemic patients. Serum total cholesterol (sTC) and serum triglyceride (sTG) were significantly reduced during niceritrol administration. Lipoprotein electrophoresis showed that niceritrol increased the alpha:beta ratio. HDL-Ch showed a significant increase of 12.5% by the 16th week of therapy. This increase was more marked in patients with lower pre-treatment HDL-Ch levels and significant in patients whose pre-treatment sTG levels were in excess of 200 mg/dl. Females displayed higher pre-treatment HDL-Ch levels (38.5 mg/dl) than males (30.6 mg/dl). However, niceritrol increased HDL-Ch significantly in both groups. At 16 weeks, the VLDL- + LDL-Ch level showed a significant decrease of 9.2%; the HDL-Ch:VLDL + LDL-Ch and HDL-CH:sTC ratios were significantly increased throughout niceritrol administration. Niceritrol is thought to be effective in preventing the development and progression of atherosclerosis because it raises the level of anti-atherogenic HDL-Ch and lowers the level of atherogenic VLDL- + LDL-Ch.

Continuous ammonia monitor using a Stark microwave cavity resonator

An ammonia monitor has been made by using a rectangular Stark microwave cavity tightly coupled through an iris to a Gunn oscillator. The Stark electrode installed inside the cavity is provided with a 100 kHz sinusoidal modulation voltage and a dc sweep voltage. The oscillation of the Gunn diode is tuned with the coupled Stark cavity to a frequency near a J,K=3,3 transition (23870.1 MHz) of ammonia. By fixing the Stark dc bias to a voltage which gives a peak intensity of the derivative output of the electric-resonance signal, ammonia is continuously monitored. An extremely good long-term stability is obtained. The noise level corresponds to 0.08 ppm of ammonia.

Primary structure of murine major histocompatibility complex alloantigens: amino acid sequence of the amino-terminal one hundred and seventy-three residues of the H-2Kb glycoprotein

The amino-terminal 173 residues of the murine histocompatibility antigen H-2Kb have been assigned by using radiochemical methodology. The complete sequence of an 86 residue glycopeptide (CN-Ib), which is one of the five major CNBr fragments of Kb, was determined by analysis of peptides obtained from digests using thrombin and V8 staphylococcal protease. Complete sequences were obtained for the three large thrombic peptides, and these were aligned by using peptides from the V8 protease digest. Alignment of the CNBr fragments was carried out by using [35S]Met-labeled peptides from a tryptic digest of the papain-cleaved H-2Kb molecule. Positive identification was possible for all the common amino acids except Asp (Asp) which was indirectly assigned and which is designated in italics. The sequence obtained in our studies was Gly-Pro-His-Ser-Leu-Arg-Tyr-Phe-Val-Thr-Ala-Val-Ser-Arg-Pro-Gly-Leu-Gly-Glu-Pro-Arg-Tyr-Met-Glu-Val-Gly-Tyr-Val-Asp-Asp-Thr-Glu-Phe-Val-Arg-Phe-Asp-Ser-Asp-Ala-Glu-Asn-Pro-Arg-Tyr-Glu-Pro-Arg-Ala-Arg-Trp-Met-Glu-Gln-Glu-Gly-Pro-Glu-Tyr-Trp-Glu-Arg-Glu-Thr-Gln-Lys-Ala-Lys-Gly-Asn-Glu-Gln-Ser-Phe-Arg-Val-Asp-Leu-Arg-Thr-Leu-Leu-Gly-Tyr-Tyr-(Asn)-Gln-Ser-Lys-Gly-Gly-Ser-His-Thr-Ile-Gln-Val-Ile-Ser-Gly-Cys-Glu-Val-Gly-Ser-Asp-Gly-Arg-Leu-Leu-Arg-Gly-Tyr-Gln-Gln-Tyr-Ala-Tyr-Asp-Gly-Cys-Asp-Tyr-Ile-Ala-Leu-Asn-Glu-Asp-Leu-Lys-Thr-Trp-Thr-Ala-Ala-Asp-Met-Ala-Ala-Leu-Ile-Thr-Lys-His-Lys-Trp-Glu-Gln-Ala-Gly-Glu-Ala-Glu-Arg-Leu-Arg-Ala-Tyr-Leu-Glu-Gly-Thr-Cys-Val-Glu-Trp-Leu-Arg-Arg-Tyr-Leu-Lys. These data represent the longest reported amino acid sequence determined by utilizing radiochemical methodology and provide the first extensive information on the primary structure of murine histocompatibility antigens.

Thermosensitive, extracellular neutral proteases in Bacillus subtilis: isolation, characterization, and genetics

Two mutants (NT02 and NT17), each producing a thermosensitive neutral protease, were isolated from Bacillus subtilis NP58, a transformant which acquired the property of hyperproduction of neutral protease from Bacillus natto IAM 1212. The neutral proteases produced by these two mutants were partially purified and enzymologically characterized. The two mutant neutral proteases displayed increased thermosensitivity as well as altered pH optima compared with those of the NP58 enzyme. In addition, the hydrolytic activity of the thermosensitive neutral proteases on synthetic peptide substrates was found to be extremely different. These results strongly suggest that the site of mutation in each of the temperature-sensitive strains is located within the structural gene for neutral protease (nprE). Previous studies indicated the existence of a specific regulator gene (nprR) in addition to the structural gene for neutral protease. Phage PBS1-mediated transduction and deoxyribonucleic acid-mediated transformation studies with the parental and mutant strains suggest that the chromosomal order of these genes is recA-pyrA-nprR-nprE-fruB-metC. Moreover, the results of these genetic analyses imply that the mutations to thermosensitivity are located proximate to each other within the nprE gene.

Characteristics of impaired chemotactic function in cord blood leukocytes

Mobilities of cord blood granulocytes were studied using the agarose plate method and Boyden's chamber method. In the agarose plate, granulocytes of cord blood were shown to have moderately decreased responses in chemotaxis and chemokinesis induced by Escherichia coli-derived chemotactic factor and/or zymosan-activated serum, whereas they were shown to have a normal capacity of random mobility. Although their distance and index of chemotaxis or chemokinesis in the agarose plate were significantly less than those of adult granulocytes, response rate in both types of mobility were evidently higher compared with those in patients with chemotactic defect. Furthermore, there is a difference between chemotactic responses of cord blood granulocytes to E. coli-derived chemotactic factor and to zymosan-activated serum in the agarose plate method. Using the latter, a more distinguishable difference between chemotactic responses of cord blood granulocytes and adult granulocytes was shown. The Boyden's chamber method tended to show a more significant difference between chemotactic responses of granulocytes of cord blood and adults than in the agarose plate method.

Primary structure of murine major histocompatibility complex alloantigens: amino acid sequence studies of the cyanogen bromide fragments of the H-2Kb glycoprotein

Radiochemical microtechniques have been used in the amino acid sequence analysis of five major CNBr fragments of the glycoprotein specified by the murine major histocompatibility complex gene H-2k(b). These fragments have been tentatively aligned and represent the NH(2)-terminal 80% of the intact molecule. All amino acids except Asp, Asn, and Gln have been assigned in 128 out of 149 possible positions in the NH(2)-terminal portions of each of these fragments. These assignments, which represent approximately 50% of the total sequence from these fragments, are listed below in the order of their alignment in the intact H-2K(b) molecule: IIIn, -PHSLRYFVTAVSRP(G)L(G)(E)PRYM; IIIa, EVGYV--TEFVRF-S-AE(A)PRYEPR(A)--M; Ib, E-EGPEYWERET-KAK(G)-E-SFR--LRTLL(G)YY--TK; Ia, AALITK-KWE-AGEAERLRAYLEGTC-E-L; Ic, ELVETRPAG-GTF-KWAS-VVPLGKE-YY(T). The unassigned positions represented by dashes in the above sequences may be tentatively assigned as Asp, Asn, or Gln. The NH(2)-terminal sequence obtained for the H-2K(b) molecule was compared to the limited sequence information available for other major histocompatibility complex gene products. An 84% homology (16 of 19 residues) to the H-2K(q) and H-2K(k) molecules, which are identical to one another in the positions compared, was observed. A similar comparison with 28 of the 31 NH(2)-terminal residues of HLA-B7 indicated 68% homology. Furthermore, significant homology was observed between H-K(b) and HLA-B7 in a region of glycosylation, which occurs between positions 85 and 100 in the two molecules.

Primary structure of murine major histocompatibility complex alloantigens: isolation, biochemical characterization, and preliminary alignment of CNBr fragments from the H-2Ib glycoprotein

Radiochemical methodology has been applied in studies directed toward the determination of the amino acid sequence of the murine H-2Kb gene product. Five major CNBr fragments, which comprise the NH2-terminal 80% of the intact glycoprotein and include the H-2Kb fragment isolated by papain cleavage, were isolated and characterized. By means of amino-terminal sequence analysis, homology to other products of the major histocompatibility complex, identification of partial CNBr cleavage products, and localization of the site of papain cleavage, it was possible to align the fragments obtained from the molecule in the following order: the NH2-terminal fragment, designated IIIn, contains 23 residues and is followed by fragment IIIa, which contains 29 residues. Two peptides Ib (Mr 11,500) and Ia (Mr 12,000), each of which contains a carbohydrate moiety, are followed by fragment Ic (Mr 5800), which includes the site of papain cleavage. The data indicate the presence of disulfide bonds between fragments Ib and Ia and between Ia and Ic.

Convulsion following intrathecal cephaloridine

Following therapeutic intrathecal administration of cephaloridine to an 11-day-old premature infant with suspected meningitis, a generalized tonic convulsion was observed. Symptoms continued to subside over the next six hours, followed by postictal sleep. That convulsion and other symptoms were due to cephaloridine was confirmed when the second intrathecal administration produced the same symptom. Because of its possible damaging effect on CNS, it is strongly suggested that cephaloridine should not be administered directly into the cerebrospinal fluid space.

Regulation of neutral protease productivity in Bacillus subtilis: transformation of high protease productivity

A transformable strain of Bacillus subtilis 6160, a derivative of B. subtilis 168, produces three kinds of casein hydrolytic enzymes (alkaline protease, neutral protease, and esterase) in a culture medium. B. natto IAM 1212 produces 15 to 20 times as much total proteolytic activity as does B. subtilis. Extracellular proteases produced by the two strains were separated into each enzyme fraction by diethylaminoethyl-Sephadex A-50 column chromatography. The difference in the total protease activities of extracellular proteases between the two strains was due to the amount of neutral protease. The ratios of neutral protease activity to alkaline protease activity (N/A) were 1.1 in B. subtilis 6160 and 13.0 in B. natto IAM 1212. Enzymological and immunological properties of alkaline protease and neutral protease obtained from the two strains were quite similar or identical, respectively. Specific activities measured by an immunological analysis of the two neutral proteases against casein were also equal. A genetic character of high protease productivity in B. natto IAM 1212 was transferred to B. subtilis 6160 by the deoxyribonucleic acid-mediated transformation. Among 73 transformants that acquired high protease productivity, 69 produced a higher amount of neutral protease and the ratios of N/A were changed to 15 to 60. Three other strains were transformed in the productivity of neutral protease and alpha-amylase simultaneously, and one showed considerable change in the production of alkaline protease and neutral protease. The specific activities (casein hydrolytic activities/enzyme molecules) of neutral proteases from the representative four transformants were equal to those of the two parental strains. These results suggested the presence of a specific gene(s) that participated in the productivity of neutral protease in B. subtilis.