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About 10,000 papers for “Matrix function”

Function of the Sperm Nuclear Matrix

Jeffrey A. Shaman, Yasuhiro Yamauchi, W. Steven Ward · Archives of Andrology · 2007

Mammalian spermatozoa contain some of the most highly compact chromatin. This is due to the DNA binding proteins, the protamines, which replace most of the histones during spermiogenesis. This chromatin, however, shares some features with somatic cell chromatin. One of these is the organization of DNA into loop domains attached at their bases to a proteinaceous nuclear matrix. Several groups have shown that the sites at which DNA associates with the sperm nuclear matrix contain chromatin structures that are linked with specific functions. Recent data also suggest that the sperm nuclear matrix plays essential roles in the paternal pronucleus of the newly fertilized oocyte, suggesting that the sperm cell provides more information to the new embryo than solely the genetic material it delivers. Here, we will review these data which together give insight into the functional significance and requirements of sperm nuclear structure.

Cited by 56

Matrix Metalloproteinases: From Structure to Function

Marco Fragai, Claudio Luchinat · 2015

The structural diversity of the proteins and glycoproteins forming the extracellular matrix (ECM) has prompted the evolution and diversification of the human matrix metalloproteinases (MMPs). The sequence of events occurring at the active site of MMPs while functioning has been largely revealed by investigating the hydrolysis of peptide models. The conformational rearrangement of the active site, suggested by the slight differences among the crystal structures, along the steps of the catalytic mechanism, accounts for a relatively large internal mobility of the catalytic domain in MMP-12. The hydrolysis of cross-linked elastin and of type I collagen are two illustrative examples of the complexity of the enzymatic activity of MMPs. The analysis of the highest maximum occurrence (MO) structures of FL-MMP-1 provides another piece of information on the behaviour of the protein and shows that the conformational space explored by FL-MMP-1 in solution strongly supports the mechanism.

Cited by 1

Recent advances in nuclear matrix function.

Mohan C. Vemuri, Nomula Raju, S. K. Malhotra · PubMed · 1993

The nuclear matrix in eukaryotes is a non-histone proteinaceous nucleoskeleton structure having attachment sites for DNA loops during DNA replication. The nuclear matrix has been implicated in transcription, regulation of gene expression, primary transcription processing and provides a mooring for certain hormone receptors. Moreover, the nuclear matrix protein has linkages to intermediate filaments of the cytoskeleton. This review presents recent advances concerning the involvement of the nuclear matrix in DNA replication, relaxation of the superhelical strain in DNA, processing of hnRNA and snRNP, and RNA transport.

Cited by 11

Differentiation of an Exponential Matrix Function

Oliver Linton, J. Roderick McCrorie · Econometric Theory · 1995

An abstract is not available for this content so a preview has been provided. Please use the Get access link above for information on how to access this content.

Cited by 6

Realizations of the transfer-function matrix

W. Gawroński, H. G. Natke · International Journal of Systems Science · 1987

A new procedure based on the decomposition of the Hankel matrix is used to determine the realization of the transfer-function matrix. The realization obtained is transformed to the balanced one, and this allows its minimality to be evaluated.

Cited by 4

The enamel organic matrix: structureand function

Alexandre Ribeiro do Espírito Santo, Sérgio Roberto Peres Line · LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) · 2006

Dental enamel is the most mineralized tissue in the vertebrate body and contains the largest known biologically formed hydroxyapatite crystals. Its formation occurs extracellularly through the collaboration of a proteic transient framework (the enamel organic matrix), which controls hydroxyapatite crystal growth, morphology and orientation. This matrix is deposited with a small amount of mineral during the secretory stage of amelogenesis. The organic components begin to be degraded in the transition stage and are extensively corrupted, and almost entirely replaced by the inorganic crystallites during maturation stage. The present paper reviews current knowledge on the structural biology of the enamel organic matrix.

Cited by 8Open access

[Structure and function of matrix metalloproteinases].

Krzysztof H. Olszyński, Małgorzata Zimowska · PubMed · 2009

The ECM remodeling is a finely orchestrated process that involves changes in expression of the ECM genes and the activity of proteinases to clear the previous ECM deposit. Among enzymes involved in ECM remodeling, zinc-dependent proteinases--matrix metalloproteinases (MMPs) are believed to be the ones of major importance. MMPs degrade the ECM components and regulate the bioavailability and/or activity of growth factors by cleavage of both matrix and non-matrix substrates or by mediating receptor turnover. This review introduces the members of the MMP family and discusses their domain structure and function, proenzyme activation and the mechanism of inhibition.

Cited by 22

Generating function for rotation matrix elements

Selda Akdemir, Emin Öztekin · International Journal of Quantum Chemistry · 2011

Abstract The rotation matrix elements are expressed in terms of the Jacobi, Hypergeometric, and Legendre polynomials in the literature. In this study, the generating function is presented for rotation matrix elements by using properties of Jacobi polynomials. In addition, some special values and Rodrigues' formula of rotation matrix elements are obtained by using the generating function. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012

Cited by 0

Scales Of Function And Matrix Spaces

Alfred M. Dahma · D-Scholarship@Pitt (University of Pittsburgh) · 2009

The following work is divided into three chapters. In the first chapter, we extend the classical definition of Lebesgue function spaces to include values of p < 0. If (&Omega;,&Sigma;, μ) is a finite, non-atomic measure space, μ a positive measure, then we denote by M(μ) the space of equivalence classes of &Sigma;-measurable functions. For all p > 0, L−p(µ) is the set M(μ) together with a complete, translation invariant metric, d−p, defined using the decreasing rearrangement of functions ƒ ∈ M(μ). Defined as such, we can extend the inclusion Lq (μ) ⊂ Lp (μ) to all real numbers p and q, with p < q. Furthermore, L−p(μ) can be equipped with an F-norm defined by ||f|| = d−p(f, 0). The second chapter deals with the theory of Hilbert frames. We prove several inequalities relating the Schatten norm of the frame operator, S, to the p-norms of the frame elements, ƒj. This is done first in finite dimensional Hilbert spaces, then extended to infinite dimensions using a truncated frame operator for finite subsets of the frame. In the final section of this chapter, we construct a frame for which the averaged 1-norm of the associated Gram matrix exhibits an optimal growth rate. In the paper Generalized Roundness and Negative Type, Lennard, Tonge, and Westonshow that the geometric notion of generalized roundness in a metric space is equivalent tothat of negative type. Using this equivalent characterization, along with classical embedding theorems, the authors prove that for p > 2, L p fails to have generalized roundness q for any q > 0. It is noted, as a consequence, that the Schatten class C p, for p > 2, has maximal generalized roundness 0. In the third chapter, we prove that this result remains true for p in the interval (0, 2).

Cited by 1Open access

Melvin Moss’ function matrix theory—Revisited

Stephanos Kyrkanides, Todd M. Moore, Jen‐nie H. Miller et al. · Orthodontic Waves · 2010

The functional matrix theory was first introduced in the orthodontic literature by Melvin Moss half century ago. Since its original introduction, several attempts have been made to test the validity of this theory with mixed results. In this paper, we present evidence generated using transgenic mice to test the role of neuronal function in craniofacial development. Our data confirmed previous observations that midface retrusion accompanied neuronal dysfunction in the HexB−/− mouse model of Sandhoff disease. Importantly, restoration of neuronal function after targeted expression of a therapeutic gene selectively in the neurons of HexB−/− mice resulted in normalization of midface development in this mouse model. Histological analysis of the cranial base revealed that abnormal development of the synchondroses underlies the attendant midface retrusion in this model: Neuronal dysfunction led to the absence of hypertrophic chondrocytes in the synchondroses, whereas restoration of neuronal function resulted in normalization of the cranial base development. Taken together, our studies suggest that neuronal function is critical for normal midface development, underscoring the importance of the functional matrix theory as originally proposed by Melvin Moss.

Cited by 13

Infinite Matrix Products and the Representation of the Matrix Gamma Function

J.‐C. Cortés, L. Jódar, Francisco J. Solís et al. · Abstract and Applied Analysis · 2015

We introduce infinite matrix products including some of their main properties and convergence results. We apply them in order to extend to the matrix scenario the definition of the scalar gamma function given by an infinite product due to Weierstrass. A limit representation of the matrix gamma function is also provided.

Cited by 11Open access