Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.69 (botulinum neurotoxin)
 1,901 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have used a set of synthetic overlapping peptides encompassing the entire heavy (H) chain of botulinum neurotoxin serotype A (BoNT/A) to map, in two mouse strains (BALB/c, H2d, and SJL, H2S), the regions on the H-chain recognized by Abs in the last bleed of non-protective anti-BoNT/A antisera and in the bleed of protective antisera immediately following it in the bleeding schedule. Although the protective antisera bound slightly higher amounts of total (IgG+IgM) Abs, non-protective and protective BALB/c antisera showed similar peptide-binding profiles involving peptides N6/N7, N25, C2/C3, C9/C10/C11, C15, C18, C24, C30, and C31 and, at lower amounts of bound Abs, peptides N19, C6/C7, and C28. IgG+IgM antibodies of the protective SJL antisera recognized peptides N5, N22, and C21, and these peptides were only slightly recognized (N22, C21) or unrecognized (N5) by the non-protective antisera. Additionally, peptides N7/N8, N25, C11, C15, and less so N27/N28 bound two-fold or more Abs from the SJL protective antisera than the non-protective antisera. The Abs bound to peptides C4 and C29 were of relatively lower affinity. Peptides C2/C3, C7, C18/C19, C24, C30, and C31 bound higher amounts of Abs in the SJL protective versus the non-protective antisera, but the differences were less than double. We also mapped the binding profiles of the IgG Abs in these sera. BALB/c and SJL had 13-36-fold higher of IgG Abs that bound to BoNT/A in the protective antisera relative to non-protective antisera. The IgG Abs in the protective antisera of each mouse haplotype bound to the same peptides that bound total Abs in the correlate antiserum. But in both mouse strains, the non-protective Abs showed little or no IgG Abs that bound to these peptides. In the SJL haplotype, the IgG response to peptide N5 was transient, appearing strongly in early protective Abs and disappearing by day 70. It is not clear whether the response to region N5 plays a role in initiating and contributing to the protective activity of the toxin in the SJL strain in the early stages but is not needed in later hyperimmune stages of the Ab response. It is concluded that the switch in BALB/c and SJL mice from non-protective to protective Abs is not associated with major changes in the epitope-recognition profiles. Although some slight differences between non-protective and protective antisera appeared in their levels of Abs that were bound by some peptides, these differences are not sufficient to explain differences in the protection properties. Protection was mostly associated with the immunoglobulin class of the antibodies. IgM antibodies were non-protective, while IgG Abs produced after the switch were protective.
 ...
PMID:Submolecular recognition profiles in two mouse strains of non-protective and protective antibodies against botulinum neurotoxin A. 1595 Jul 44

The purpose of this work was to map the entire recognition profile of the H chain of botulinum neurotoxin A (BoNT/A) by Abs in sera that have protective anti-BoNT/A Abs by the mouse protection assay (MPA) from cervical dystonia (CD) patients who had been treated with botulinum neurotoxin, serotype A (BOTOX). In previous studies we found that human anti-tetanus neurotoxin (TeNT) Abs cross-react with BoNT/A and BoNT/B. In the present work we devised an assay procedure for measuring specific anti-BoNT/A Abs in human sera by absorbing out or inhibiting the anti-TeNT Abs with TeNT before analyzing the sera for the anti-BoNT/A Abs. The sera were obtained from 28 CD patients who had become unresponsive to treatment with BoNT/A and the sera were found to protect mice against a lethal dose of BoNT/A. For localization of the Ab-binding regions on the H chain we employed a set of sixty, 19-residue synthetic peptides (except for peptide C31 which was 22 residues) that encompassed the entire H chain sequence 449-1296 and overlapped consecutively by five residues. The pattern of Ab recognition varied from patient to patient, but a very limited set of peptides were recognized by most of the patients. These were, in decreasing amounts of Ab binding, peptide N25 (H chain residues 785-803), C9/C10 (967-985/981-999), C31 (1275-1296), C15 (1051-1069), C20 (1121-1139), N16 (659-677), N22 (743-761), and N4 (491-509). But not every serum recognized all these peptides. The finding that the binding profile was not the same for all the patients is consistent with previous observations that immune responses to protein antigens are under genetic control and that the response to each epitope within a protein is under separate genetic control. Except for the region within C9/C10, the other regions either coincided (N16 and C31), or overlapped (N4, N22, N25, C15 and C20), with the recently mapped synaptosomes (snps)-binding regions on the H chain. The molecular and clinical implications of these findings are discussed.
 ...
PMID:Mapping of the regions on the heavy chain of botulinum neurotoxin A (BoNT/A) recognized by antibodies of cervical dystonia patients with immunoresistance to BoNT/A. 1664 21

Cervical dystonia (CD) is due to neck-muscle spasms that cause pain and involuntary contractions resulting in abnormal neck movements and posture. Symptoms can be relieved by injecting the affected muscle with a botulinum neurotoxin (BoNT, usually type A or type B). The therapeutic benefits are impermanent and toxin injections need to be repeated every 3-6 months. In a very small percentage of patients (less with BoNT/A than with BoNT/B) the treatment elicits blocking anti-toxin antibodies (Abs), which reduce or terminate the patient's responsiveness to further treatment. We have recently mapped (Dolimbek et al., 2006) the CD sera Ab-binding profile using a panel of 60, 19-residue peptides that encompassed the entire H chain sequence 449-1296 and overlapped consecutively by 5 residues. Abs in CD sera bound to one or more of the peptides N25, C10, C15, C20, and C31. This suggested the possibility that binding to these peptides could be used for assay of Abs in CD sera. Data analysis reported here found that Ab binding to these regions showed very significant deviations from the control responses. Of these four peptides, C10 showed the most significant level of separation between patient and control groups (p = 5 x 10(-7)) and the theoretical resolution (i.e., ability to distinguish CD patients from control, see full definition under 'Statistical analysis' in Methods), 84%, was about 4% higher than the least resolved response, C31 (p = 6 x 10(-6), resolution 80%). Since the amounts of Abs bound to a given peptide varied with the patient and not all the patients necessarily recognized all four peptides, there was the possibility that binding to combinations of two or more peptides might give a better discriminatory capability. Using two peptides, C10 plus C31, the resolution improved to 87% (p = 4 x 10(-8)). These two peptides appeared to compliment each other and negate the lower resolution of C31. Combination of three peptides gave resolutions that ranged from 85 (N25 + C15 + C31; p = 2 x 10(-7)) to 88% (C10 + C15 + C31; p = 1 x 10(-8)). Finally, using the data of all four peptides, N25 + C10 + C15 + C31, gave a resolution of 86% (p = 1 x 10(-7)). Although these levels of resolution are somewhat lower than that obtained with whole BoNT/A (resolution 97%; p = 6 x 10(-12)), it may be concluded that the two-peptide combination C10 + C31, or the three-peptide combination C10 + C15 + C31 (affording resolutions of 87 and 88%, respectively) provide a good diagnostic, toxin-free procedure for assay of total specific anti-toxin Abs in BoNT/A-treated CD patients.
 ...
PMID:A peptide-based immunoassay for antibodies against botulinum neurotoxin A. 1698 Dec 47

We determined the entire profile of the continuous antigenic regions recognized by blocking antibodies (Abs) in sera from 30BoNT/B-treated cervical dystonia (CD) patients who developed unresponsiveness to treatment. The sera protected mice against a lethal dose of BoNT/B. We analyzed Ab binding to a panel of 60 synthetic 19-residue peptides (peptide C31 was 24 residues) that overlapped consecutively by 5 residues and encompassed the entire BoNT/B heavy (H) chain (residues 442-1291). Most Abs recognized a limited set of peptides but the pattern and Ab levels bound varied with the patient, consistent with genetic control of immune responses and with responses to each epitope being separately controlled. Abs were bound by peptides (in decreasing order): C1 (residues 848-866), C10 (974-992), C16 (1058-1076), C14 (1030-1048), N15 (638-656), N21/N22 (722-740/736-754), N24/N25 (764-782/778-796) and N29 (834-852). Peptides N3/N4 (470-488/484-502), N27 (806-824), C2 (862-880), C4 (890-908), C6/C7 (918-936/932-950), C17 (1072-1090), C24 (1170-1188), C29 (1240-1258) and C31 (1268-1291) exhibited low Ab binding. The remaining peptides bound little or no Abs. Of the 30 antisera, 28 (93.3%) had Abs that bound to peptides C1, C10, C14 or C16, and 27 (90.0%) bound to peptide N22. No peptide was recognized by all the antisera, but peptide combinations N24+C1, N22+N24+C1, N24+C1+C10, C10+C14+C16, N22+N24+C1+C10, C1+C10+C14+C16 or N22+N24+C1+C10+C14 bound blocking Abs in 30 (100%) antisera. BoNT/B-treated CD patients had higher Ab levels and bound to more epitopes (at least 11) than did BoNT/A-treated patients (5 regions). The regions recognized by anti-BoNT/B Abs occupied surface areas that displayed no correlation to surface electrostatic potential, hydrophilicity, hydrophobicity, or temperature factor. These regions afford candidates for epitope-specific manipulation of anti-toxin immune responses.
 ...
PMID:Molecular recognition of botulinum neurotoxin B heavy chain by human antibodies from cervical dystonia patients that develop immunoresistance to toxin treatment. 1867 21