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Kumar NN, Pizzo ME, Nehra G, Wilken-Resman B, Boroumand S, Thorne RG. Passive Immunotherapies for Central Nervous System Disorders: Current Delivery Challenges and New Approaches. Bioconjug Chem 2018; 29:3937-3966. [PMID: 30265523 DOI: 10.1021/acs.bioconjchem.8b00548] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Passive immunotherapy, i.e., the administration of exogenous antibodies that recognize a specific target antigen, has gained significant momentum as a potential treatment strategy for several central nervous system (CNS) disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and brain cancer, among others. Advances in antibody engineering to create therapeutic antibody fragments or antibody conjugates have introduced new strategies that may also be applied to treat CNS disorders. However, drug delivery to the CNS for antibodies and other macromolecules has thus far proven challenging, due in large part to the blood-brain barrier and blood-cerebrospinal fluid barriers that greatly restrict transport of peripherally administered molecules from the systemic circulation into the CNS. Here, we summarize the various passive immunotherapy approaches under study for the treatment of CNS disorders, with a primary focus on disease-specific and target site-specific challenges to drug delivery and new, cutting edge methods.
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Kumar NN, Lochhead JJ, Pizzo ME, Nehra G, Boroumand S, Greene G, Thorne RG. Delivery of immunoglobulin G antibodies to the rat nervous system following intranasal administration: Distribution, dose-response, and mechanisms of delivery. J Control Release 2018; 286:467-484. [PMID: 30081144 DOI: 10.1016/j.jconrel.2018.08.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/28/2018] [Accepted: 08/02/2018] [Indexed: 12/31/2022]
Abstract
The intranasal route has been hypothesized to circumvent the blood-brain and blood-cerebrospinal fluid barriers, allowing entry into the brain via extracellular pathways along olfactory and trigeminal nerves and the perivascular spaces (PVS) of cerebral blood vessels. We investigated the potential of the intranasal route to non-invasively deliver antibodies to the brain 30 min following administration by characterizing distribution, dose-response, and mechanisms of antibody transport to and within the brain after administering non-targeted radiolabeled or fluorescently-labeled full length immunoglobulin G (IgG) to normal adult female rats. Intranasal [125I]-IgG consistently yielded highest concentrations in the olfactory bulbs, trigeminal nerves, and leptomeningeal blood vessels with their associated PVS. Intranasal delivery also resulted in significantly higher [125I]-IgG concentrations in the CNS than systemic (intra-arterial) delivery for doses producing similar endpoint blood concentrations. Importantly, CNS targeting significantly increased with increasing dose only with intranasal administration, yielding brain concentrations that ranged from the low-to-mid picomolar range with tracer dosing (50 μg) up to the low nanomolar range at higher doses (1 mg and 2.5 mg). Finally, intranasal pre-treatment with a previously identified nasal permeation enhancer, matrix metalloproteinase-9, significantly improved intranasal [125I]-IgG delivery to multiple brain regions and further allowed us to elucidate IgG transport pathways extending from the nasal epithelia into the brain using fluorescence microscopy. The results show that it may be feasible to achieve therapeutic levels of IgG in the CNS, particularly at higher intranasal doses, and clarify the likely cranial nerve and perivascular distribution pathways taken by antibodies to reach the brain from the nasal mucosae.
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Affiliation(s)
- Niyanta N Kumar
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Madison, WI 53705, United States
| | - Jeffrey J Lochhead
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Madison, WI 53705, United States
| | - Michelle E Pizzo
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Madison, WI 53705, United States; Clinical Neuroengineering Training Program, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Geetika Nehra
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Madison, WI 53705, United States
| | - Sam Boroumand
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Madison, WI 53705, United States
| | - Gretchen Greene
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Madison, WI 53705, United States
| | - Robert G Thorne
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Madison, WI 53705, United States; Clinical Neuroengineering Training Program, University of Wisconsin-Madison, Madison, WI 53705, United States; Neuroscience Training Program & Center for Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, United States; Cellular and Molecular Pathology Graduate Training Program, University of Wisconsin-Madison, Madison, WI 53705, United States.
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Pizzo ME, Wolak DJ, Kumar NN, Brunette E, Brunnquell CL, Hannocks M, Abbott NJ, Meyerand ME, Sorokin L, Stanimirovic DB, Thorne RG. Intrathecal antibody distribution in the rat brain: surface diffusion, perivascular transport and osmotic enhancement of delivery. J Physiol 2018; 596:445-475. [PMID: 29023798 PMCID: PMC5792566 DOI: 10.1113/jp275105] [Citation(s) in RCA: 170] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 09/29/2017] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS It is unclear precisely how macromolecules (e.g. endogenous proteins and exogenous immunotherapeutics) access brain tissue from the cerebrospinal fluid (CSF). We show that transport at the brain-CSF interface involves a balance between Fickian diffusion in the extracellular spaces at the brain surface and convective transport in perivascular spaces of cerebral blood vessels. Intrathecally-infused antibodies exhibited size-dependent access to the perivascular spaces and tunica media basement membranes of leptomeningeal arteries. Perivascular access and distribution of full-length IgG could be enhanced by intrathecal co-infusion of hyperosmolar mannitol. Pores or stomata present on CSF-facing leptomeningeal cells ensheathing blood vessels in the subarachnoid space may provide unique entry sites into the perivascular spaces from the CSF. These results illuminate new mechanisms likely to govern antibody trafficking at the brain-CSF interface with relevance for immune surveillance in the healthy brain and insights into the distribution of therapeutic antibodies. ABSTRACT The precise mechanisms governing the central distribution of macromolecules from the cerebrospinal fluid (CSF) to the brain and spinal cord remain poorly understood, despite their importance for physiological processes such as antibody trafficking for central immune surveillance, as well as several ongoing intrathecal clinical trials. In the present study, we clarify how IgG and smaller single-domain antibodies (sdAb) distribute throughout the whole brain in a size-dependent manner after intrathecal infusion in rats using ex vivo fluorescence and in vivo three-dimensional magnetic resonance imaging. Antibody distribution was characterized by diffusion at the brain surface and widespread distribution to deep brain regions along the perivascular spaces of all vessel types, with sdAb accessing a four- to seven-fold greater brain area than IgG. Perivascular transport involved blood vessels of all caliber and putative smooth muscle and astroglial basement membrane compartments. Perivascular access to smooth muscle basement membrane compartments also exhibited size-dependence. Electron microscopy was used to show stomata on leptomeningeal coverings of blood vessels in the subarachnoid space as potential access points allowing substances in the CSF to enter the perivascular space. Osmolyte co-infusion significantly enhanced perivascular access of the larger antibody from the CSF, with intrathecal 0.75 m mannitol increasing the number of perivascular profiles per slice area accessed by IgG by ∼50%. The results of the present study reveal potential distribution mechanisms for endogenous IgG, which is one of the most abundant proteins in the CSF, as well as provide new insights with respect to understanding and improving the drug delivery of macromolecules to the central nervous system via the intrathecal route.
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Affiliation(s)
- Michelle E. Pizzo
- School of PharmacyDivision of Pharmaceutical Sciences, University of Wisconsin‐MadisonMadisonWIUSA
- Clinical Neuroengineering Training ProgramUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Daniel J. Wolak
- School of PharmacyDivision of Pharmaceutical Sciences, University of Wisconsin‐MadisonMadisonWIUSA
- Clinical Neuroengineering Training ProgramUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Niyanta N. Kumar
- School of PharmacyDivision of Pharmaceutical Sciences, University of Wisconsin‐MadisonMadisonWIUSA
| | - Eric Brunette
- Human Health Therapeutics Research CentreNational Research Council of CanadaOttawaCanada
| | | | - Melanie‐Jane Hannocks
- Institute of Physiological Chemistry and PathobiochemistryMuenster UniversityMuensterGermany
- Cells‐in‐Motion Cluster of ExcellenceMuenster UniversityMuensterGermany
| | - N. Joan Abbott
- Institute of Pharmaceutical ScienceKing's College LondonLondonUK
| | - M. Elizabeth Meyerand
- Clinical Neuroengineering Training ProgramUniversity of Wisconsin‐MadisonMadisonWIUSA
- Department of Medical PhysicsUniversity of Wisconsin‐MadisonMadisonWIUSA
- Department of Biomedical EngineeringUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Lydia Sorokin
- Institute of Physiological Chemistry and PathobiochemistryMuenster UniversityMuensterGermany
- Cells‐in‐Motion Cluster of ExcellenceMuenster UniversityMuensterGermany
| | - Danica B. Stanimirovic
- Human Health Therapeutics Research CentreNational Research Council of CanadaOttawaCanada
| | - Robert G. Thorne
- School of PharmacyDivision of Pharmaceutical Sciences, University of Wisconsin‐MadisonMadisonWIUSA
- Clinical Neuroengineering Training ProgramUniversity of Wisconsin‐MadisonMadisonWIUSA
- Neuroscience Training ProgramUniversity of Wisconsin‐MadisonMadisonWIUSA
- Cellular and Molecular Pathology Graduate ProgramUniversity of Wisconsin‐MadisonMadisonWIUSA
- Institute for Clinical and Translational ResearchUniversity of Wisconsin‐MadisonWIUSA
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Cheloha RW, Chen B, Kumar NN, Watanabe T, Thorne RG, Li L, Gardella TJ, Gellman SH. Development of Potent, Protease-Resistant Agonists of the Parathyroid Hormone Receptor with Broad β Residue Distribution. J Med Chem 2017; 60:8816-8833. [PMID: 29064243 DOI: 10.1021/acs.jmedchem.7b00876] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The parathyroid hormone receptor 1 (PTHR1) is a member of the B-family of GPCRs; these receptors are activated by long polypeptide hormones and constitute targets of drug development efforts. Parathyroid hormone (PTH, 84 residues) and PTH-related protein (PTHrP, 141 residues) are natural agonists of PTHR1, and an N-terminal fragment of PTH, PTH(1-34), is used clinically to treat osteoporosis. Conventional peptides in the 20-40-mer length range are rapidly degraded by proteases, which may limit their biomedical utility. We have used the PTHR1-ligand system to explore the impact of broadly distributed replacement of α-amino acid residues with β-amino acid residues on susceptibility to proteolysis and agonist activity. This effort led us to identify new PTHR1 agonists that contain α → β replacements throughout their sequences, manifest potent agonist activity in cellular assays, and display remarkable resistance to proteolysis, in cases remaining active after extended exposure to simulated gastric fluid. The strategy we have employed suggests a path toward identifying protease-resistant agonists of other B-family GPCRs.
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Affiliation(s)
- Ross W Cheloha
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Bingming Chen
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Niyanta N Kumar
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Tomoyuki Watanabe
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts 02114, United States
| | - Robert G Thorne
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States.,Clinical Neuroengineering Training Program, University of Wisconsin-Madison Biomedical Engineering , Engineering Centers Building, Room 2120, 1550 Engineering Drive, Madison Wisconsin 53706, United States.,Neuroscience Training Program & Center for Neuroscience, Wisconsin Institutes for Medical Research II , Rooms 9531 and 9533, 1111 Highland Avenue, Madison, Wisconsin 53705, United States.,Cellular and Molecular Pathology Graduate Training Program, UW Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison , 1685 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.,School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts 02114, United States
| | - Samuel H Gellman
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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Kumar NN, Gautam M, Lochhead JJ, Wolak DJ, Ithapu V, Singh V, Thorne RG. Relative vascular permeability and vascularity across different regions of the rat nasal mucosa: implications for nasal physiology and drug delivery. Sci Rep 2016; 6:31732. [PMID: 27558973 PMCID: PMC4997340 DOI: 10.1038/srep31732] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/25/2016] [Indexed: 12/25/2022] Open
Abstract
Intranasal administration provides a non-invasive drug delivery route that has been proposed to target macromolecules either to the brain via direct extracellular cranial nerve-associated pathways or to the periphery via absorption into the systemic circulation. Delivering drugs to nasal regions that have lower vascular density and/or permeability may allow more drug to access the extracellular cranial nerve-associated pathways and therefore favor delivery to the brain. However, relative vascular permeabilities of the different nasal mucosal sites have not yet been reported. Here, we determined that the relative capillary permeability to hydrophilic macromolecule tracers is significantly greater in nasal respiratory regions than in olfactory regions. Mean capillary density in the nasal mucosa was also approximately 5-fold higher in nasal respiratory regions than in olfactory regions. Applying capillary pore theory and normalization to our permeability data yielded mean pore diameter estimates ranging from 13–17 nm for the nasal respiratory vasculature compared to <10 nm for the vasculature in olfactory regions. The results suggest lymphatic drainage for CNS immune responses may be favored in olfactory regions due to relatively lower clearance to the bloodstream. Lower blood clearance may also provide a reason to target the olfactory area for drug delivery to the brain.
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Affiliation(s)
- Niyanta N Kumar
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Room #5113, Rennebohm hall, 777 Highland avenue, Madison, WI - 53705, USA
| | - Mohan Gautam
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Room #5113, Rennebohm hall, 777 Highland avenue, Madison, WI - 53705, USA
| | - Jeffrey J Lochhead
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Room #5113, Rennebohm hall, 777 Highland avenue, Madison, WI - 53705, USA
| | - Daniel J Wolak
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Room #5113, Rennebohm hall, 777 Highland avenue, Madison, WI - 53705, USA.,Clinical Neuroengineering Training Program, University of Wisconsin-Madison Biomedical Engineering, Engineering Centers Building, 1550 Engineering Drive, Room #2120, Madison WI - 53706, USA
| | - Vamsi Ithapu
- Department of Computer Sciences, University of Wisconsin-Madison, 5780 Medical Sciences Center, 1300 University Avenue, Madison, WI - 53706, USA
| | - Vikas Singh
- Department of Computer Sciences, University of Wisconsin-Madison, 5780 Medical Sciences Center, 1300 University Avenue, Madison, WI - 53706, USA
| | - Robert G Thorne
- Pharmaceutical Sciences Division, University of Wisconsin-Madison School of Pharmacy, Room #5113, Rennebohm hall, 777 Highland avenue, Madison, WI - 53705, USA.,Clinical Neuroengineering Training Program, University of Wisconsin-Madison Biomedical Engineering, Engineering Centers Building, 1550 Engineering Drive, Room #2120, Madison WI - 53706, USA.,Neuroscience Training Program &Center for Neuroscience, Rooms 9531 &9533, Wisconsin Institutes for Medical Research II, 1111 Highland Ave. Madison, WI - 53705, USA.,Cellular and Molecular Pathology Graduate Training Program, University of Wisconsin-Madison, UW Department of Pathology and Laboratory Medicine 1685 Highland Avenue Madison, WI - 53705, USA
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Parker LM, Tallapragada VJ, Kumar NN, Goodchild AK. Distribution and localisation of Gα proteins in the rostral ventrolateral medulla of normotensive and hypertensive rats: focus on catecholaminergic neurons. Neuroscience 2012; 218:20-34. [PMID: 22626648 DOI: 10.1016/j.neuroscience.2012.05.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 05/11/2012] [Accepted: 05/12/2012] [Indexed: 02/07/2023]
Abstract
About 860 G-protein-coupled receptors (GPCRs) mediate their actions via heterotrimeric G-proteins. Their activation releases Gα from Gβλ subunits. The type of Gα subunit dictates the major signalling proteins involved: adenylyl cyclase, PLC and rhoGEF. The rostral ventrolateral medulla (RVLM), containing the rostral C1 (rC1) cell group, sets and maintains the tonic and reflex control of blood pressure and a plethora of inputs converge onto these neurons. We determined the relative abundance of 10 Gα subunit mRNAs, representing the four major families, within the RVLM, using quantitative RT-PCR. In situ hybridisation (ISH) combined with immunohistochemistry (IHC) was used to quantify and compare this expression in rC1 with that in the A1 and A5 cell groups. The relative abundance of Gα subunit mRNAs and a comparison of gene expression levels were quantitatively determined in normotensive and hypertensive rat strains. All 10 Gα mRNAs were detected in the RVLM of Sprague-Dawley (SD) rats with relative abundance such that Gαs>Gαi2>Gαo>Gαq>GαL>Gα11>Gαi3>Gαi1>Gα12>Gα13. The high abundance of Gα mRNAs signalling via adenylyl cyclase indicates the importance of associated GPCRs. Within the rC1 and A1 groups similar differential Gα mRNA expression profiles were seen with Gαs being found in all rC1 cells, Gα11 absent and Gαi3 rarely expressed. Thus functionally distinct subgroups exist within the rC1 and A1 cell groups as differing distributions of Gα subunits must reflect the array of GPCRs that influence their activity. In contrast, all A5 cells expressed all Gα mRNAs suggesting a functionally homogeneous group. When the 10 Gα mRNAs of the RVLM in spontaneously hypertensive rats (SHR) were compared quantitatively to Wistar-Kyoto (WKY), only Gαs and Gα12 were significantly elevated. However when the expression in normotensive SD and WKY was compared with SHR no significant differences were evident. These findings demonstrate a range of GPCR signalling capabilities in brainstem neurons important for homeostasis and suggest a prominent role for signalling via adenylyl cyclase.
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Affiliation(s)
- L M Parker
- The Australian School of Advanced Medicine, 2 Technology Place, Macquarie University, 2109 NSW, Australia
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Kumar NN, Allen K, Parker L, Damanhuri H, Goodchild AK. Neuropeptide coding of sympathetic preganglionic neurons; focus on adrenally projecting populations. Neuroscience 2010; 170:789-99. [PMID: 20674686 DOI: 10.1016/j.neuroscience.2010.07.047] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 07/20/2010] [Accepted: 07/22/2010] [Indexed: 01/04/2023]
Abstract
Chemical coding of sympathetic preganglionic neurons (SPN) suggests that the chemical content of subpopulations of SPN can define their function. Since neuropeptides, once synthesized are transported to the axon terminal, most demonstrated chemical coding has been identified using immunoreactive terminals at the target organ. Here, we use a different approach to identify and quantify the subpopulations of SPN that contain the mRNA for pituitary adenylate cyclase activating polypeptide (PACAP) or enkephalin. Using double-labeled immunohistochemistry combined with in situ hybridization (ISH) we firstly identified the distribution of these mRNAs in the spinal cord and determined quantitatively, in Sprague-Dawley rats, that many SPN at the T4-T10 spinal level contain preproPACAP (PPP+, 80 ± 3%, n=3), whereas a very small percentage contain preproenkephalin (PPE+, 4 ± 2%, n=4). A similar neurochemical distribution was found at C8-T3 spinal level. These data suggest that PACAP potentially regulates a large number of functions dictated by SPN whereas enkephalins are involved in few functions. We extended the study to explore those SPN that control adrenal chromaffin cells. We found 97 ± 5% of adrenally projecting SPN (AP-SPN) to be PPP+ (n=4) with only 47 ± 3% that were PPE+ (n=5). These data indicate that adrenally projecting PACAPergic SPN regulate both adrenal adrenaline (Ad) and noradrenaline (NAd) release whereas the enkephalinergic SPN subpopulation must control a (sub) population of chromaffin cells - most likely those that release Ad. The sensory innervation of the adrenal gland was also determined. Of the few adrenally projecting dorsal root ganglia (AP-DRG) observed, 74 ± 12% were PPP+ (n=3), whereas 1 ± 1% were PPE+ (n=3). Therefore, if sensory neurons release peptides to the adrenal medulla, PACAP is most likely involved. Together, these data provide a neurochemical basis for differential control of sympathetic outflow particularly that to the adrenal medulla.
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Affiliation(s)
- N N Kumar
- The Australian School of Advanced Medicine, Faculty of Human Sciences, Macquarie University, Sydney, NSW, 2109, Australia
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Abstract
Cellulomonas is a unique bacterium possessing not only the capacity to degrade various carbohydrates, such as starch, xylan and cellulose, but crystalline cellulose as well. It has developed a complex battery of glucanases to deal with substrates possessing such extensive microheterogeneities. Some of these enzymes are multifunctional, as well as cross inducible, possessing a multi-domain structure; these enzymes are thought to have arisen by the shuffling of these domains. Intergeneric hybrids have been constructed between Cellulomonas and Zymomonas so as to enhance the industrial potential of this organism. This review examines the unique features of this microorganism and evaluates its key role in the conversion of complex wastes to useful products, by virtue of its unusual attributes.
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Affiliation(s)
- P Chaudhary
- Molecular Biology Research Laboratory, Department of Zoology, University of Poona, Pune-411 007, India
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Abstract
Diverse functional roles of multifunctional proteins arise from either their independent functional domains or dual activities mediated through a single active site. Presence of multifunctional proteins significantly enhances the metabolic efficiency of a cell. Microorganisms utilising complex substrates with extensive microheterogeneities, such as carbohydrates evolved batteries of multifunctional glucanases, facilitating parsimonious utilisation of these substrates. Various attempts have since been made to artificially construct these glucanases. Analysis of information on various glucanases would be helpful in understanding the evolutionary interrelationship between this class of enzymes and will give an insight into the structural features controlling different unrelated activities. This review examines the genesis, evolution and structural features of multifunctional glucanases.
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Affiliation(s)
- N N Kumar
- Molecular Biology Research Laboratory, Department of Zoology, University of Pune, Pune-411 007, India
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Pillai PK, Shroff N, Kumar NN, Tripathi AK. Photoconductivity and dark-conductivity studies of CdS1-xSex(Cu) sintered layers. Phys Rev B Condens Matter 1985; 32:8228-8233. [PMID: 9937003 DOI: 10.1103/physrevb.32.8228] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Kumar NN, Joseph PP, Ramachandran M, Varghese S, Das KV. Renal changes in rheumatoid arthritis. J Assoc Physicians India 1982; 30:423-5. [PMID: 7169465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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