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H Lackland

Publications and source records attributed to H Lackland.

29 records · Page 2Linked to original sources
PubMed1970

Induction of rabbit antibody with molecular uniformity after immunization with group C streptococci.

Antibodies with uniform properties may occur in rabbits after immunization with Group C streptococci. These precipitating antibodies possess specificity for the group-specific carbohydrate. Not uncommonly, their concentration is between 20 and 40 mg/ml of antiserum. Evidence for molecular uniformity in the case of one of these antibodies, described in detail here, includes: individual antigenic specificity; monodisperse distribution of the light chains by alkaline urea polyacrylamide disc electrophoresis; and a single amino acid in each of the first three N-terminal positions of the light chains. When the amino acid sequence of rabbit antibody b+ light chains (kappa type) are aligned against their human kappa counterparts, a definite homology is observed between the N-terminus of the human and the rabbit variable region.

Amino Acid Sequence↗
PubMed1969

Amino acid sequence restriction in rabbit antibody light chains.

Light chains were obtained from IgG rabbit antibodies to the group-specific carbohydrates of groups A and C streptococci. An analysis of the amino acid alternatives which exist at the first three positions of the N-terminus in both light-chain preparations shows a marked restriction in amino acid sequence heterogeneity when compared with preimmune light chains. Both of these related, but immunologically distinct, antigenic determinants select the same uncommon subpopulation of rabbit light chains.

Amino Acid Sequence↗
PubMed1969

Chemical studies on the structure of mucopeptide isolated from Streptococcus bovis.

Mucopeptides isolated from Streptococcus bovis cell walls were found to be composed of alanine, glutamic acid, lysine, and threonine in a mole ratio of 3:1:1:1. A dipeptide, N(epsilon)-lysylthreonine, was isolated from S. bovis mucopeptide by ion-exchange chromatography. This finding suggests that threonine is associated with the bridge which cross-links adjacent tetrapeptides by connecting the epsilon-amino group of lysine of one tetrapeptide to the carboxyl group of d-alanine of another to form the mucopeptide matrix.

Alanine↗
PubMed1968

Immunochemical studies on the cross-reactivity between streptococcal and staphylococcal mucopeptide.

Particulate mucopeptides of Group A-variant streptococci and Staphylococcus aureus, solubilized by ultrasonic treatment, give a precipitin reaction with the sera of rabbits immunized with Group A-variant streptococci. gamma-G globulin antibodies have been recovered from these sera which react with the mucopeptides but not with the Group A-variant carbohydrate. The immunochemical basis for the cross-reactivity between the streptococcal and staphylococcal mucopeptides was investigated in detail. Three chemically different fractions have been isolated from enzymatic digests of staphylococcal mucopeptide and were employed as haptenic inhibitors of the precipitin reaction. A fraction consisting of the peptide moiety of mucopeptide was the strongest inhibitor, whereas the hexosamine-rich fraction was less effective. The third fraction, rich in glycine, was least effective. It is suggested that the immunologic cross-reactivity between streptococcal and staphylococcal mucopeptide is due to the fact that these two substances contain chemically similar tetrapeptides. The hexosamine polymer which is identical for both mucopeptides may also contribute to their cross-reactivity.

Amino Acids↗
PubMedDate not supplied

Presentation of peptide antigens as albumin conjugates for use in detection of serum antibodies by enzyme-linked immunosorbent assay.

The use of linear peptides as antigens for detection of serum antibodies has been studied using a sequence of the Borrelia burgdorferi protein, flagellin, and Lyme disease sera as a model. It was found that a novel presentation of the peptide as a hapten on the carrier protein, bovine serum albumin, in the enzyme-linked immunosorbent assay format can be successfully applied to distinguish between Lyme disease and control sera.

Amino Acids↗
PubMedDate not supplied

An acridine amino acid derivative for use in Fmoc peptide synthesis.

An acridine derivative of N-alpha-Fmoc-lysine has been prepared and used in solid phase peptide synthesis. The fluorescence properties of the acridine reporter group are retained throughout the peptide synthesis procedure. The utility of the acridine group was demonstrated by its use as an energy acceptor in a fluorescence energy-quenching assay with trypsin.

Acridines↗
PubMedDate not supplied

Synthesis of the pro-peptide of subtilisin BPN'.

Subtilisin, a bacterial serine protease, is secreted as pre-pro-subtilisin. Previously, we demonstrated that the pro-peptide moiety of intact pro-subtilisin can guide the folding of inactive protein to active enzyme both in an intramolecular (6) and intermolecular manner (18). Herein is reported the total chemical synthesis of the pro-sequence (77 amino acids) of pre-pro-subtilisin BPN' carried out by solid phase methods. The structure was confirmed by both sequencing and amino acid analysis of the fragment peptides resulting from a V-8 protease digest. Preliminary studies indicate that the synthetic pro-peptide itself can renature denatured subtilisin BPN'. This study demonstrates a novel method for examining protein folding with the aid of exogenously added synthetic peptides.

Amino Acid Sequence↗