China
Africa
Explore chapters and articles related to this topic
Enzymatic Degradation of Bradykinin
Published in Sami I. Said, Proinflammatory and Antiinflammatory Peptides, 2020
Randal A. Skidgel, Ervin G. Erdös
Metallocarboxypeptidases hydrolyze peptides with the participation of a tightly bound zinc cofactor (Skidgel, 1996); carboxypeptidase A-type or carboxypeptidase B-type enzymes belong here. Carboxypeptidase B-type enzymes cleave only basic C-terminal Arg or Lys amino acids (Skidgel, 1988), and because Bk and congeners contain a C-terminal Arg, they are substrates of carboxypeptidase B-type enzymes.
Biochemical Effects in Animals
Published in Stephen P. Coburn, The Chemistry and Metabolism of 4′-Deoxypyridoxine, 2018
Vogel et al.532 included deoxypyridoxine in their comparison between aromatic and nonaromatic compounds as enzyme inhibitors. Deoxypyridoxine hydrochloride, pyridoxine hydrochloride, and pyridoxamine hydrochloride all caused 50% inhibition of carboxypeptidase B at about 7 × 10−5 Mand catalase at 1 × 10”” M. Pyridoxal phosphate was slightly more effective. None of these compounds inhibited carboxypeptidase A or peroxidase. Deoxypyridoxine (1.5 mg/day per mouse) did not affect the response of uterine peroxidase or liver catalase to estrogen. Pressey397 studied the effect of pyridoxine analogs on invertases from potato, Neurospora, and yeast. Pyridoxine and deoxypyridoxine were generally comparable in their inhibitory effect which the author postulates results from the pyridine ring analogous to the effect of aniline, another aromatic base.
Affinity Modification in Biochemistry, Biology, and Applied Sciences
Published in Dmitri G. Knorre, Valentin V. Vlassov, Affinity Modification of Biopolymers, 1989
Dmitri G. Knorre, Valentin V. Vlassov
The cases are described when strong inhibition due to coordination of the ligand to the metal ion in the active center takes place. Thus, 2-benzyl-3-mercaptopropanoic acid (SQ 14,603) is a strong inhibitor of carboxypeptidase A, specifically cleaving C-terminal aromatic amino acid residues (see Chapter 1, Section I.A). The dissociation constant of the enzymeinhibitor complex is Ki = 1.1 × 10−8M, whereas for carboxypeptidase B specific to C-terminal positively charged amino acid residues Ki = 1.6 × 10−4 M. At the same time 2-mercaptomethyl-5-guanidinopentanoic acid (SQ 24,798) has a Ki of 4 × 10−10M vs. carboxypeptidase B and a Ki of 1.2 × 10−5M vs. carboxypeptidase A. In this case the inhibitory action is due to coordination to a catalytically essential Zn2+ ion.395
Comprehensive characterisation of the heterogeneity of adalimumab via charge variant analysis hyphenated on-line to native high resolution Orbitrap mass spectrometry
Published in mAbs, 2019
Florian Füssl, Anne Trappe, Ken Cook, Kai Scheffler, Oliver Fitzgerald, Jonathan Bones
Using our native CVA-MS approach, we were able to obtain very high chromatographic resolution and successful identification of the majority of the 16 charge variants observed. Among them were proteoforms modified by different levels of C-terminal lysine truncation, deamidation, succinimide aspartic acid (Asp) formation, glycation and fragmentation. To investigate whether host cell proteins (HCPs) might be involved in the fragmentation of adalimumab, we performed an HCP analysis employing peptide mapping. Several HCPs were detected, among them the protease Cathepsin L, which could suggest the occurrence of the detected fragments to partly be due to enzymatic proteolysis. Carboxypeptidase B (CpB) digestion and peptide mapping experiments were performed as orthogonal methods to confirm the results obtained on the intact protein level.
Assessment of structural and functional similarity of biosimilar products: Rituximab as a case study
Published in mAbs, 2018
Neh Nupur, Nidhi Chhabra, Rozaleen Dash, Anurag S. Rathore
CEX-HPLC was performed to quantify charge variants on MAbPac SCX-10 RS, BioLC™ (4.6 × 250 mm, 5 μm, Thermo Scientific) column operated at 25°C using Dionex Ultimate 3000 RSLC system (Thermo Scientific) consisting of a quaternary pump with a degasser, an auto sampler with a cooling unit, and a DAD. Prior to injection, the column was saturated with 95% mobile phase A (15 mM sodium phosphate buffer and 0.05% NaN3 at pH 6.2) and 5% mobile phase B (150 mM sodium phosphate buffer and 0.05% NaN3 at pH 6.2). All buffers were filtered with a 0.22 μm cutoff nylon membrane filter (Pall Corporation) and degassed prior to use. 20 μg sample was loaded and differently charged species were separated using a 13 min sigmoidal gradient from 5% – 35% B at a flow rate of 1 ml/min.41 Detection was performed by monitoring UV absorbance at 280 nm. For C terminal lysine cleavage, 15 μL of 1 mg/mL carboxypeptidase B (CpB, Sigma-Aldrich; Cat# C9584) was added to 1 mL of sample and the mixture was incubated at 37°C for 30 min. Chromeleon software (Thermo Scientific) was used for chromatogram integration and estimating acidic, basic and main content through relative peak area percentage values.
Quality comparability assessment of a SARS-CoV-2-neutralizing antibody across transient, mini-pool-derived and single-clone CHO cells
Published in mAbs, 2022
Gangling Xu, Chuanfei Yu, Wenbo Wang, Cexiong Fu, Hongchuan Liu, Yanping Zhu, Yuan Li, Chunyu Liu, Zhihao Fu, Gang Wu, Meng Li, Sha Guo, Xiaojuan Yu, Jialiang Du, Yalan Yang, Maoqin Duan, Yongfei Cui, Hui Feng, Lan Wang
CEX HPLC was performed on an e2695 HPLC system (Waters Corporation) equipped with a UV detector set at 280 nm and a MabPac SCX-10 column (10 μm, 4.0 × 250 mm; Thermo Fisher Scientific). Samples were diluted to 1.0 mg/mL with mobile phase A (20 mM of MES; pH: 6.0) and treated with 250:1 (v/v) (protein:enzyme) of carboxypeptidase B (1 mg/mL) at 37°C for 1 h. Approximately 100 μL of sample was injected onto the column at 60% mobile phase A and 40% mobile phase B (20 mM of MES + 100 mM of NaCl; pH: 6.0). After 3 min, the sample was eluted with a linear gradient of 40–80% mobile phase B within 40 min. The LC flow rate was fixed at 1.0 mL/min and the temperature of the column was 40°C.