Forckenbeckstraße 6,

D-52074 Aachen

Biological rhythms (beating of the heart, circadian sleep cycles, respiration, and the release of hormones) are necessary to sustain life. Heart beating is the most reliable and rhythmic biological phenomenon. Cardiac pacemaking is produced by the slow diastolic depolarization phase of the action potential. The hyperpolarization-activated cation current (termed If, Ih, or Iq) plays a key role in the in the initiation and modulation of cardiac and neuronal pacemaker depolarization. The generation of cardiac pacemaker potentials relies on a complex interplay between at least four different types of cation channels: T- and L-type Ca2+ channels, K+ channels, and a cation channel termed If (synonymous names are Ih and Iq). The If channel has been designated as "pacemaker" channel because it reveals unique features that are believed to be a prerequisite for pacemaker activity. Recently, the hyperpolarization-activated cyclic nucleotide-gated families of ion channel proteins (HCN1-4) have been identified as the "pacemaker" channel. The amino acid sequences of HCNs predict a structure similar to that of voltage-gated (Kv) channels and cyclic nucleotide-gated (CNG) channels. HCNs proteins (HCN1-4) are characterized by six transmembrane domains (S1-S6), including a including a positively charged voltage-sensing S4 segment and an ion-conducting pore between S5 and S6. In the C terminus the HCNs carry a cyclic nucleotide-binding domain (CNBD), a motif found in several cyclic nucleotide-binding proteins. The core region of HCNs channels (S1 to the C terminus of the CNBD) is highly conserved, whereas the cytoplasmic N and C-termini,

vary considerably in their length and share only weak sequence homology. The functional HCN, like other members of the superfamily of voltage-gated cation channels, channels probably assemble into tetrameric complexes.

HCN1, also known as Brain cyclic nucleotide channel gated 1, BCNG1 or HAC-2 (mouse/rat 910 aa, human 749-aa), is primarily expressed in brain. In mouse, HCN1 is mainly expressed in the neocortex, the CA1 region of the hippocampus, the superior colliculus, and in the molecular cell layer of the cerebellum.

HCN2, also known as Brain cyclic nucleotide channel gated 2, BCNG2 or HAC-1 (rat 834 aa, human 889-aa, chromosome 19p13.3), is primarily expressed in brain. In mouse, HCN1 is mainly expressed in brain (olfactory bulb and cerebral cortex, hippocampus, thalamus, cerebellum etc) and heart (ventricles and atrium).

HCN3 or HAC3 (rat 780-aa, mouse 779-aa, human 703 aa) has been detected in brain but its expression was much less than other HCNs. Its expression was also detected in liver, lung, and kidney of mouse by some researchers but not by others.

HCN4 (rat 1198 aa, human 1203-aa, chromosome 15q24-q25) is highly expressed at heart ventricle and atrium, brain (olfactory bulb, thalamus), and testis. expressed in brain.

 

M= Mouse; R=Rat; H=Human; Ha=Hamster; Rb=Rabbit; B=Bovine; CT= near C-terminus; NT=near N-terminus; Internal=Middle of protein.

m=mouse; r=rat; h=human; b=bovine; d=dog; ~CT or ~NT=near C or N-terminus. EC=Extracellular; CP=Cytoplasmic domain; Control peptides (unconjugated, free, antigenic peptides), because of their small size, are not recommended for Western. They should be used in ELISA/antibody blocking studies.

* Expected antibody crossreactivity information is mostly based upon high (>70%) sequence conservation of antigenic/control peptides in various species. When antibody crossreactivity has actually been experimentally confirmed in various species, it will be mentioned in the appropriate data sheets.

"Neat Antisera or antisera" are the unpurified antiserum and it is suitable for ELISA and Western.
"Affinity pure" IgG may be more suitable for immunohistochemical (IHC) applications and to reduce background in most immunological applications including ELISA and Western.
"Control peptides" can not be used for Western as they are very short peptides. They are intended for ELISA or antibody blocking studies to establish antibody specificity.
Western blot +ve protein controls, where available, are semi-pure, pure or recombinant proteins that are formulated in SDS-PAGE sample buffer. They are recommended to be used for Western (load 10 ul/lane) for visualization with antibodies.
 

© 2005 GENTAUR bvba
 

Bioxys, HIV p24, TNF a, IFN gamma, Agarose