scholarly journals Structure of the CLC-1 chloride channel from Homo sapiens

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Eunyong Park ◽  
Roderick MacKinnon
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Proton Transfer ◽  
Opposite Direction ◽  
Chloride Channel ◽  
Pore Diameter ◽  
Homo Sapiens ◽  
Transport Function ◽  
Key Sites ◽  
Internal Pore

CLC channels mediate passive Cl− conduction, while CLC transporters mediate active Cl− transport coupled to H+ transport in the opposite direction. The distinction between CLC-0/1/2 channels and CLC transporters seems undetectable by amino acid sequence. To understand why they are different functionally we determined the structure of the human CLC-1 channel. Its ‘glutamate gate’ residue, known to mediate proton transfer in CLC transporters, adopts a location in the structure that appears to preclude it from its transport function. Furthermore, smaller side chains produce a wider pore near the intracellular surface, potentially reducing a kinetic barrier for Cl− conduction. When the corresponding residues are mutated in a transporter, it is converted to a channel. Finally, Cl− at key sites in the pore appear to interact with reduced affinity compared to transporters. Thus, subtle differences in glutamate gate conformation, internal pore diameter and Cl− affinity distinguish CLC channels and transporters.

The staining pattern of the tropomyosin sequence is displayed in a new paracrystal

1986 ◽  
Vol 44 ◽  
pp. 150-151
Author(s):  
M.K. Lamvik ◽  
L.L. Klatt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Staining Pattern ◽  
Banding Patterns ◽  
Mass Thickness ◽  
New Form

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.

Isolation and Structural Charaderization of a Potent Inhibitor of Coagulation Factor Xa from the Leech Haementeria ghilianii

1989 ◽  
Vol 61 (03) ◽  
pp. 437-441 ◽  
Author(s):  
Cindra Condra ◽  
Elka Nutt ◽  
Christopher J Petroski ◽  
Ellen Simpson ◽  
P A Friedman ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Salivary Gland ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Western Blot ◽  
Potent Inhibitor ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Sds Page ◽  
Bovine Factor

SummaryThe present work reports the discovery and charactenzation of an anticoagulant protein in the salivary gland of the giant bloodsucking leech, H. ghilianii, which is a specific and potent inhibitor of coagulation factor Xa. The inhibitor, purified to homogeneity, displayed subnanomolar inhibition of bovine factor Xa and had a molecular weight of approximately 15,000 as deduced by denaturing SDS-PAGE. The amino acid sequence of the first 43 residues of the H. ghilianii derived inhibitor displayed a striking homology to antistasin, the recently described subnanomolar inhibitor of factor Xa isolated from the Mexican leech, H. officinalis. Antisera prepared to antistasin cross-reacted with the H. ghilianii protein in Western Blot analysis. These data indicate that the giant Amazonian leech, H. ghilianii, and the smaller Mexican leech, H. officinalrs, have similar proteins which disrupt the normal hemostatic clotting mechanisms in their mammalian host’s blood.

Paris I Dysfibrinogenemia: A Point Mutation in Intron 8 Results in Insertion of a 15 Amino Acid Sequence in the Fibrinogen γ-Chain

1993 ◽  
Vol 69 (03) ◽  
pp. 217-220 ◽  
Author(s):  
Jonathan B Rosenberg ◽  
Peter J Newman ◽  
Michael W Mosesson ◽  
Marie-Claude Guillin ◽  
David L Amrani
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Point Mutation ◽  
Genomic Dna ◽  
Comparative Sequence Analysis ◽  
Chain Gene ◽  
Molecular Defect ◽  
Nucleotide Position ◽  
Normal Individuals ◽  
Polymerase Chain

SummaryParis I dysfibrinogenemia results in the production of a fibrinogen molecule containing a functionally abnormal γ-chain. We determined the basis of the molecular defect using polymerase chain reaction (PCR) to amplify the γ-chain region of the Paris I subject’s genomic DNA. Comparative sequence analysis of cloned PCR segments of normal and Paris I genomic DNA revealed only an A→G point mutation occurring at nucleotide position 6588 within intron 8 of the Paris I γ-chain gene. We examined six normal individuals and found only normal sequence in this region, indicating that this change is not likely to represent a normal polymorphism. This nucleotide change leads to a 45 bp fragment being inserted between exons 8 and 9 in the mature γparis I chain mRNA, and encodes a 15 amino acid insert after γ350 [M-C-G-E-A-L-P-M-L-K-D-P-C-Y]. Alternative splicing of this region from intron 8 into the mature Paris I γ-chain mRNA also results after translation into a substitution of S for G at position γ351. Biochemical studies of 14C-iodoacetamide incorporation into disulfide-reduced Paris I and normal fibrinogen corroborated the molecular biologic predictions that two additional cysteine residues exist within the γpariS I chain. We conclude that the insertion of this amino acid sequence leads to a conformationallyaltered, and dysfunctional γ-chain in Paris I fibrinogen.

Complete Covalent Structure of Human Platelet Factor 4

1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Human Platelet ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Disulphide Bonds ◽  
Covalent Structure

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.

The minimal amino acid sequence of the insulin-potentiating fragments of human growth hormone: its mechanism of action

Diabetes ◽  
1980 ◽  
Vol 29 (10) ◽  
pp. 782-787 ◽  
Author(s):  
F. M. Ng ◽  
J. Bornstein ◽  
C. E. Pullin ◽  
J. O. Bromley ◽  
S. L. Macaulay
Keyword(s):  
Growth Hormone ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Human Growth Hormone ◽  
Mechanism Of Action ◽  
Human Growth
Sign in / Sign up

Export Citation Format

Share Document